In depth analysis of the Athens Riviera climate and palm potential

[Victor G.]

6 minutes ago, Alicante said:

Oh, thanks for that map, do you have another one regarding the SE Islands such as Rhodes and Kasos? It's indeed far from normal for this season!

True!

I don't want to flood the topic with images, so check out here: http://www.meteo.gr/climate

 

Set it to "last 30 days" and you can easily see the Tmax and Tmin deviations everywhere!

 

 

[southathens]

7 hours ago, Alicante said:

Nice garden. I have one question, how UHI-influenced is? Looking at the info/pics you've provided, it seems to be in a strong UHI area, as it's in a high density urbanised area and it also looks sheltered by bigger nearby buildings. And yes, it's of course better to have some plants/grass below than just concrete, but I don't know its impact on a rooftop.

It's nice to see that garden on that rooftop. Cities in Europe should do more rooftop gardens like people do in New York. Since we don't have too much available space on the ground (as all it's filled with buildings) rooftops are a good option to reduce UHI, heat and to reduce pollution. So do you think Nea Smyrni is 1-2ºC warmer than Downtown Athens?

UHI is always an issue when we discuss urban stations and especially in big cities like Athens. This is why using Davis fan aspirated stations like NOA is an excellent option to reduce these kind of biases. These stations are specifically designed for accurate urban readings but it is inescapable that UHI will be there no matter what. As the Davis network expands internationally both from public authorities and private entities we will have a clearer idea of the actual climate  where the vast majority  of people lives which is urban settings and in turn we can compare reliably their values with the same type of stations. 

Generally speaking however, having studied the Athens climate for many years I can say with confidence that the NOA Davis stations actually under report day maximum Ts compared to WMO Athens stations. This is due to the amazing mechanical ventilation offered by Davis stations which effectively cancels out most of the T biases. Bear in mind also that UHI in Athens according to many studies is almost not seen in maximum Ts due to Athens's complex orography which has a huge impact on its air circulation (especially in the summer). My feeling is that if we had WMO stations scattered just next to NOA stations in Athens we would be baffled of how ridiculously high Ts  we would see.  I would not be surprised if some of these passive WMO stations in these very same areas where the warmest Athens NOA stations are located would register mean annual Ts of close to 21°C. 

In fact, I confidently expect a WMO value of around 21°C average annual temperature in the warmest areas of urban Athens after having studied the city's climate for so many years . It's a pity that HNMS does not use the countless small parks or other private locations in urban Athens as much.  I am sure we  would get some shocking values for an area in Continental Europe. 

To answer your question, South Athens and the Athens Riviera is generally much warmer than Downtown Athens in terms of winter maxes since it is at a lower altitude and close to the moderating effects of the sea.  This is to be expected in one of the most complex climatologically  speaking areas of the world such as Athens. The complexity of Athens's orography, its countainless hills even inside the city, surrounding  mountains, huge differences in terms of altitudes even in neighbouring areas and varying distances from the sea make Athens a real challenge and joy at the same time when we study its climate. I am still learning almost everyday a new fact regarding the complex climatic diversity of Athens. 

 

[southathens]

8 hours ago, Victor G. said:

True!

I don't want to flood the topic with images, so check out here: http://www.meteo.gr/climate

 

Set it to "last 30 days" and you can easily see the Tmax and Tmin deviations everywhere!

I just hope they could have published the averages from all NOA stations! It would make my job so much easier instead of having to calculate them from the output myself! But hey , still 53 stations is significant!

[Phoenikakias]

17 hours ago, Manos33 said:

Καλησπέρα ξανά! Ξέρεις σε ποιά όδο βρίσκεται ακριβώς ώστε να περάσω να το δω και εγώ μια από αυτές τις μέρες?

Βασιλέως Παύλου. Βγάλε και καμία φωτογραφία σημερινή για να δούμε πως πάει!

[southathens]

4 minutes ago, Phoenikakias said:

Βασιλέως Παύλου. Βγάλε και καμία φωτογραφία σημερινή για να δούμε πως πάει!

Θυμάσαι περίπου νούμερο ή έστω σε πιο ύψος είναι? Είναι μεγάλη η Βασιλέως Παύλου. 

[Phoenikakias]

2 hours ago, Manos33 said:

UHI is always an issue when we discuss urban stations and especially in big cities like Athens. This is why using Davis fan aspirated stations like NOA is an excellent option to reduce these kind of biases. These stations are specifically designed for accurate urban readings but it is inescapable that UHI will be there no matter what. As the Davis network expands internationally both from public authorities and private entities we will have a clearer idea of the actual climate  where the vast majority  of people lives which is urban settings and in turn we can compare reliably their values with the same type of stations. 

Generally speaking however, having studied the Athens climate for many years I can say with confidence that the NOA Davis stations actually under report day maximum Ts compared to WMO Athens stations. This is due to the amazing mechanical ventilation offered by Davis stations which effectively cancels out most of the T biases. Bear in mind also that UHI in Athens according to many studies is almost not seen in maximum Ts due to Athens's complex orography which has a huge impact on its air circulation (especially in the summer). My feeling is that if we had WMO stations scattered just next to NOA stations in Athens we would be baffled of how ridiculously high Ts  we would see.  I would not be surprised if some of these passive WMO stations in these very same areas where the warmest Athens NOA stations are located would register mean annual Ts of close to 21°C. 

In fact, I confidently expect a WMO value of around 21°C average annual temperature in the warmest areas of urban Athens after having studied the city's climate for so many years . It's a pity that HNMS does not use the countless small parks or other private locations in urban Athens as much.  I am sure we  would get some shocking values for an area in Continental Europe. 

To answer your question, South Athens and the Athens Riviera is generally much warmer than Downtown Athens in terms of winter maxes since it is at a lower altitude and close to the moderating effects of the sea.  This is to be expected in one of the most complex climatologically  speaking areas of the world such as Athens. The complexity of Athens's orography, its countainless hills even inside the city, surrounding  mountains, huge differences in terms of altitudes even in neighbouring areas and varying distances from the sea make Athens a real challenge and joy at the same time when we study its climate. I am still learning almost everyday a new fact regarding the complex climatic diversity of Athens. 

 

Στο Καβουρι απέναντι απο το Λαιμό, είχε 1 με 2 βαθμούς μεγαλύτερη θερμοκρασία το βραδυ του προπερασμένου Σαββάτου, απ' ό,τι στη Βουλιαγμένη, στο Ναυτικό Όμιλο!

[Phoenikakias]

2 minutes ago, Manos33 said:

Θυμάσαι περίπου νούμερο ή έστω σε πιο ύψος είναι? Είναι μεγάλη η Βασιλέως Παύλου. 

Στο 82 περίπου; Μετα τη θεση του πρωην σινεμά Βιολέτα προς την Βουλιαγμένης.

[southathens]

6 minutes ago, Phoenikakias said:

Στο 82 περίπου; Μετα τη θεση του πρωην σινεμά Βιολέτα προς την Βουλιαγμένης.

Τέλεια! Θα προσπαθήσω να πεταχτώ το μεθεπόμενο ΣΚ μετά και από την κακοκαιρία του ερχόμενου ΣΚ ώστε να έχουμε μια ξεκάθαρη εικόνα. 

[Victor G.]

1 hour ago, Manos33 said:

Τέλεια! Θα προσπαθήσω να πεταχτώ το μεθεπόμενο ΣΚ μετά και από την κακοκαιρία του ερχόμενου ΣΚ ώστε να έχουμε μια ξεκάθαρη εικόνα. 

Αν θυμηθείς, ρίξε και μία ενημέρωση εδώ, να έχουμε το κεφάλι μας ήσυχο

[southathens]

Ναι φυσικά. Θα στείλω και φωτό. Το θέμα είναι πότε θα καταφέρω να περάσω. Κάνω και 3 δουλειές βλέπεις!

[Victor G.]

9 minutes ago, Manos33 said:

Κάνω και 3 δουλειές βλέπεις!

Ωχ, και όλο δυσκολεύουν τα πράγματα πλέον. Εγώ είμαι στις 2 δουλειές μέχρι στιγμής στο Βερολίνο (μάθημα στο πανεπιστήμιο και λίγα ιδιαίτερα) αλλά αρχίζει και χτυπάει κι εδώ άσχημα.
Τελοσπάντως βγήκαμε εκτός θέματος. Καλή υπομονή!

[southathens]

6 hours ago, Phoenikakias said:

Στο Καβουρι απέναντι απο το Λαιμό, είχε 1 με 2 βαθμούς μεγαλύτερη θερμοκρασία το βραδυ του προπερασμένου Σαββάτου, απ' ό,τι στη Βουλιαγμένη, στο Ναυτικό Όμιλο!

Το Καβούρι πρέπει να τα σπάει στις απόλυτα ελάχιστες στην Αττική. Σίγουρα για τα νότια προάστια πρέπει να είναι η πιο ήπια περιοχή από άποψη ελαχίστων. Θυμάμαι πριν χρόνια έναν ιδιωτικό Davis σταθμό λίγα μέτρα από την ακτή στο Μεγάλο Καβούρι που έδειχνε συνεχώς 1-2 πιο πάνω ελάχιστες από την υπόλοιπη Αθηναϊκή Ριβιέρα. 

Κρίμα που δεν υπάρχει πλέον αυτός ο σταθμός...

[Alicante]

9 hours ago, Manos33 said:

UHI is always an issue when we discuss urban stations and especially in big cities like Athens. This is why using Davis fan aspirated stations like NOA is an excellent option to reduce these kind of biases. These stations are specifically designed for accurate urban readings but it is inescapable that UHI will be there no matter what. As the Davis network expands internationally both from public authorities and private entities we will have a clearer idea of the actual climate  where the vast majority  of people lives which is urban settings and in turn we can compare reliably their values with the same type of stations. 

Generally speaking however, having studied the Athens climate for many years I can say with confidence that the NOA Davis stations actually under report day maximum Ts compared to WMO Athens stations. This is due to the amazing mechanical ventilation offered by Davis stations which effectively cancels out most of the T biases. Bear in mind also that UHI in Athens according to many studies is almost not seen in maximum Ts due to Athens's complex orography which has a huge impact on its air circulation (especially in the summer). My feeling is that if we had WMO stations scattered just next to NOA stations in Athens we would be baffled of how ridiculously high Ts  we would see.  I would not be surprised if some of these passive WMO stations in these very same areas where the warmest Athens NOA stations are located would register mean annual Ts of close to 21°C. 

In fact, I confidently expect a WMO value of around 21°C average annual temperature in the warmest areas of urban Athens after having studied the city's climate for so many years . It's a pity that HNMS does not use the countless small parks or other private locations in urban Athens as much.  I am sure we  would get some shocking values for an area in Continental Europe. 

To answer your question, South Athens and the Athens Riviera is generally much warmer than Downtown Athens in terms of winter maxes since it is at a lower altitude and close to the moderating effects of the sea.  This is to be expected in one of the most complex climatologically  speaking areas of the world such as Athens. The complexity of Athens's orography, its countainless hills even inside the city, surrounding  mountains, huge differences in terms of altitudes even in neighbouring areas and varying distances from the sea make Athens a real challenge and joy at the same time when we study its climate. I am still learning almost everyday a new fact regarding the complex climatic diversity of Athens. 

 

But doesn't Downtown Athens actually have an official station? The one that shows an annual average of 19.2ºC in the 1991-2020 period. http://magazine.noa.gr/archives/4446

About the other thing well I have 2 opinions. For me, rooftop stations are not as reliable as ground based stations, but the rooftop ones are the best for urban settlements (so I agree with you here) since they're artificially boosted up by the surroundings, and the cities are built up areas, not empty areas! Urban zones always have UHI, that's an undeniable fact. 

I agree with you because I personally know it because it happens in Spain too. For example, Sevilla's data comes from the airport, in a completely different environment, far from urbanised areas and very cooled down by the cultivation fields that surround the airport. Sevilla is a very densely populated city with a ton of UHI caused by the urbanism. 

The Davis Fan Aspirated stations inside Sevilla (more if they're close to the center of the city) have annual averages around 21ºC because they're 1-2ºC warmer both during the daytime and the nighttime, especially during summers, as the airport itself shows mean lows around 20ºC but in the city itself, they are actually around 22-23ºC!

So I understand and I agree with your point because I have also checked and proved what you say there by myself! But I think it's good to have both stations to compare temps that are affected and not affected by the UHI, I mean, an official urban/rooftop station and also a station in the airport/surroundings to see the UHI effect. What do you think?

[southathens]

25 minutes ago, Alicante said:

The Davis Fan Aspirated stations inside Sevilla (more if they're close to the center of the city) have annual averages around 21ºC because they're 1-2ºC warmer both during the daytime and the nighttime, especially during summers, as the airport itself shows mean lows around 20ºC but in the city itself, they are actually around 22-23ºC!
 

As far as I know there is no reliable Davis Fan Aspirated station inside Seville that is warmer than the Nea Smyrni NOA Davis Fan Aspirated station unless of course you are referring for a specific year. The warmest reliable downtown Seville Davis Fan Aspirated station is in Triana from what I have seen so far. Which Davis stations are you referring to?

Here is the link of the Triana Davis fan aspirated station

http://www.tiempoensevilla.es/index.php 

For the same period between 2012 and 2022 of parallel operation the simple mean annual in Seville Davis  is around 0.3C less than Nea Smyrni NOA Davis station.

Edited March 14, 2022 by Manos33

[southathens]

16 minutes ago, Alicante said:

But doesn't Downtown Athens actually have an official station? 

Yes but check the maxes, the WMO station in Thisio has more than 0.5C higher maxes compared to the nearby Gazi NOA station. Which goes to show how ridiculously accurate is a well maintained Davis Fan Aspirated station  in urban settings. It basically under reports maxes in the heart of the Athenian UHI in downtown Athens compared to the WMO historical station of Thisio. 

Edited March 14, 2022 by Manos33

[Alicante]

34 minutes ago, Manos33 said:

As far as I know there is no reliable Davis Fan Aspirated station inside Seville that is warmer than the Nea Smyrni NOA Davis Fan Aspirated station unless of course you are referring for a specific year. The warmest reliable downtown Seville Davis Fan Aspirated station is in Triana from what I have seen so far. Which Davis stations are you referring to?

 

Manos, you don't need to compare always between everything, it wasn't even a comparison, just an additional statement to your point...

It was some kind of Andalusian Regional Meteo association. I've seen it on Spanish Weather forums, I don't remember it right now.

As for official AEMET/WMO stations, the warmest one in the area is Sevilla Tablada, which is again in the ground inside a field, far from UHI and from any buildings.

http://www.aemet.es/es/eltiempo/observacion/ultimosdatos?k=and&l=5790Y&w=2&datos=det&x=&f=tmax
http://www.aemet.es/es/eltiempo/observacion/ultimosdatos?k=and&l=5783&w=2&datos=det&x=&f=tmax

The first station is the Tablada one (WMO 5790Y) and the second is the Airport one (WMO 5783) just compare their temps... Tablada is around 1ºC warmer.

Sevilla Airport 1991-2020 taken from AEMET OpenData has actually an average of 19.6ºC and Tablada is somewhat warmer as you can see above.
So if the airport is 19.6ºC in 30 years of averages, Tablada is even warmer (being a ground based station in a field) +21ºC in the city center wouldn't be surprising.

Here is the Sevilla Tablada Official AEMET Station location. It's inside a Spanish Air Forces Air Base. The coordinates are 37°21'51.0"N , 6°00'21.0"W

Edited March 14, 2022 by Alicante

[southathens]

1 minute ago, Alicante said:

 +21ºC in the city center doesn't sound that strange. 

Yeah, it might actually be close but we do not have data to support this statement while in Athens we have a mean annual of 20.4C from the warmest official station of the National Observatory of Athens and for the comparable period (2012-2022) the warmest downtown reliable Davis fan aspirated in Seville still can't reach the Athenian values. 

I think the issue here is that Seville is a much smaller city compared to the vastness of Athens and indeed you would expect the UHI in Athens (well at least during the nights) to be stronger. This inadvertently makes south Athens the warmest area of continental Europe. 

Remember that HNMS from its own most recent data gives a mean annual of 19.8C for the Athens Basin treating this value the highest in the country alongside South Crete averages according to the HNMS network of stations.

http://climatlas.hnms.gr/sdi/

[Victor G.]

Okay I might be going a bit off-topic now, but upon looking at some data, I found out that this little place in Photo 1 (where I have my weather station) has a more similar climate to the Athens Riviera than the other places near it (like Nea Makri, Nea Styra).

I have mentioned it before, but this year I installed a proper WS (as opposed to the cheap one I had last year) and got some interesting readings in Photo 2.
(Don't trust the max temp readings too much, as it's not fan aspirated and tends to show a bit more sometimes. The low temps are confirmed by another temp meter though)

Just sharing

[Victor G.]

2 minutes ago, Manos33 said:

Yeah, it might actually be close but we do not have data to support this statement while in Athens we have a mean annual of 20.4C from the warmest official station of the National Observatory of Athens and for the comparable period (2012-2022) the warmest downtown reliable Davis fan aspirated in Seville still can't reach the Athenian values. 

I think the issue here is that Seville is a much smaller city compared to the vastness of Athens and indeed you would expect the UHI in Athens (well at least during the nights) to be stronger. This inadvertently makes south Athens the warmest area of continental Europe. 

Remember that HNMS from its own most recent data gives a mean annual of 19.8C for the Athens Basin treating this value the highest in the country alongside South Crete averages according to the HNMS network of stations.

http://climatlas.hnms.gr/sdi/

Attica gets considerably colder it winter that south Crete. We are able to maintain this yearly average just because of our nefarious summer heat, even the minimum stays above 25C most nights (in the centre maybe even higher)

[southathens]

1 minute ago, Victor G. said:

Okay I might be going a bit off-topic now, but upon looking at some data, I found out that this little place in Photo 1 (where I have my weather station) has a more similar climate to the Athens Riviera than the other places near it (like Nea Makri, Nea Styra).

Yep, Dikastika and the whole area around it has a unique mirco-climate. It is very obvious also from the Shinias HNMS station. The minimums are very close to the Athens Riviera minimums indeed and normally we would not expect that!

[Victor G.]

4 minutes ago, Manos33 said:

Shinias HNMS station

Do you have a link for it, where one can see its real-time readings? I can't seem to find it

[southathens]

2 minutes ago, Victor G. said:

Do you have a link for it, where one can see its real-time readings? I can't seem to find it

Here you go! 

http://www.emy.gr/emy/el/observation/sa_teleytaies_paratiriseis_stathmou?perifereia=Attiki&poli=ams_shinias

The only problem is like some other HNMS stations it reports sporadically the temps in Shinias. Give it a couple of weeks and you will see some sporadic reports. It's currently offline but save the link

[southathens]

10 minutes ago, Victor G. said:

Attica gets considerably colder it winter that south Crete. We are able to maintain this yearly average just because of our nefarious summer heat, even the minimum stays above 25C most nights (in the centre maybe even higher)

Yep, that's the reason. The monstrous Athenian summer heat. The summer means are just unfathomable for an area in continental Europe. 

[Alicante]

3 minutes ago, Manos33 said:

Yeah, it might actually be close but we do not have data to support this statement while in Athens we have a mean annual of 20.4C from the warmest official station of the National Observatory of Athens and for the comparable period (2012-2022) the warmest downtown reliable Davis fan aspirated in Seville still can't reach the Athenian values. 

I think the issue here is that Seville is a much smaller city compared to the vastness of Athens and indeed you would expect the UHI in Athens (well at least during the nights) to be stronger. This inadvertently makes south Athens the warmest area of continental Europe. 

Remember that HNMS from its own most recent data gives a mean annual of 19.8C for the Athens Basin treating this value the highest in the country alongside South Crete averages according to the HNMS network of stations.

http://climatlas.hnms.gr/sdi/

Yes, it's warmer by a couple of tenths. Because summer lows in Athens are absurdly high, I know, but on the other hand, Sevilla has quite warmer winter highs and much warmer early springs, since this is a gardening/palm forum, this is much better for palm trees than having torrid summer nights. Also Sevilla's last snowfall event was in 1954 as well as Tmaxes under 5ºC have only happened in the extreme 1954 cold spell. In Athens both snow and Tm <5ºC are rare, but they can happen, like it happened in 2022 for example.

These are the 1991-2020 official AEMET OpenData values from the Airport of Sevilla, the "coldest" station in Sevilla. The official AEMET Tablada station is around 1ºC (as you can see above in the AEMET bulletins) and sadly we don't have official stations inside the city. I rekcon Athens has more UHI of course, it's much bigger, but that's not necessarily good?

4 minutes ago, Victor G. said:

Attica gets considerably colder it winter that south Crete. We are able to maintain this yearly average just because of our nefarious summer heat, even the minimum stays above 25C most nights (in the centre maybe even higher)

Yes, the summer heat is extreme in Athens thus making it the warmest place in Greece by HNMS stations. I agree... just look at these summer means, they're crazy and by means they're definetly the warmest place in Europe during summers. The TMaxes are not the warmest but the TLows are definetly the warmest, at least in Continental Europe. 
 

[Alicante]

@Manos33 one question since you know a lot about Greek climates, are there higher extremes than the 48.0ºC 1977 Greek record from Athens and Elefsina?

I ask this because in 2021 (I don't know if you knew it) Italy settled the new European record with 48.8ºC (119.8 F) in Sicily, I saw it on the WMO site and Severe Weather. 

https://public.wmo.int/en/media/news/mediterranean-gripped-extreme-heat-new-reported-temperature-record

https://www.severe-weather.eu/europe-weather/record-heatwave-mediterranean-italy-spain-portugal-mk/

[southathens]

2 minutes ago, Alicante said:

The official AEMET Tablada station is around 1ºC (as you can see above in the AEMET bulletins) 

Yeah for 7 days it is around 1C higher. We would need data for full years to discern how much hotter Tablada is but we do get an indication that it is indeed hotter from the Seville Triana Davis station in downtown Seville.  Conversely a WMO station in Nea Smyrni would be even warmer than the 20.4C due to this consistent Tmax under reporting we see in Athens from the NOA stations compared to the WMO stations thus a 21C mean annual is far more likely in south Athens. 

Yeah its not necessarily good but it is a true representation of the actual temperatures experienced by the huge numbers of people who live in Athens. 

8 minutes ago, Alicante said:

I rekcon Athens has more UHI of course, it's much bigger, but that's not necessarily good?

[southathens]

4 minutes ago, Alicante said:

@Manos33 one question since you know a lot about Greek climates, are there higher extremes than the 48.0ºC 1977 Greek record from Athens and Elefsina?

I ask this because in 2021 (I don't know if you knew it) Italy settled the new European record with 48.8ºC (119.8 F) in Sicily, I saw it on the WMO site and Severe Weather. 

https://public.wmo.int/en/media/news/mediterranean-gripped-extreme-heat-new-reported-temperature-record

https://www.severe-weather.eu/europe-weather/record-heatwave-mediterranean-italy-spain-portugal-mk/

I think the chances of WMO actually verifying this record are very slim. The committee will take a couple of years to verify the 48.8C but from the reports I have seen so far I think the chances are higher that it will be rejected. But let's see, who knows.  

In Greece, there are are a couple readings of 50-51C in the Nea Filadelfeia and Lamia private met stations but they are all trash in my opinion. 

Edited March 14, 2022 by Manos33

[southathens]

I am going to answer this post here in English, so I will not hijack the Lindos thread.

Indeed Attica seems to have a very interesting dynamic. I am not surprised that papayas can bear fruits in the coasts of the Athens Riviera despite the fact that the past few years we have had some decent cold spells. The good thing with the cold spells in the Athens Riviera is that while it might snow during these cold snaps,  Ts rarely drop below 0C in coastal Athens and given that even settled snow can survive only a few hours in the coasts of the Athens Riviera then we would expect limited damage to tropical fruits. As long as we don't get freezes then most tropical fruits can quickly recover with minimal damage.

Last weekend I was in Nikaia area in the SW suburbs of Athens and I was surprised to see two small banana trees on the street with minimal damage despite the cold snaps so far in 2022. Nikaia of course was lucky this year and snow did not even settle,  so this probably played a significant role for the survival of the bananas. Still I would expect that after the 2021-2022 winters ,which have been highly unusual for Athens, that bananas would not survive... So you never know how a cold spell might turn out in Athens. The climate diversity in Athens is so pronounced even in neighbouring areas that only by trying we can be sure of what can actually grow here.

However don't be fooled by the cold spells the past years in Attica, temperature trends especially the past 10 years in Athens show a dramatic increase. Out of curiosity I calculated the average annual temperature of the Thiseio WMO station in Downtown Athens the past decade (2012-2021) and it works out an amazing 19.74°C. This value would be unheard of 10 years ago for an area in Continental Europe.  On top of that just recently for the first time in the meteorological history of the country HNMS gives a 19.8°C average annual temperature for the Athens Basin WMO stations. Put in the mix the fact that we already have 3 major NOA stations in South Athens recording the past decade average annual temperatures ranging from 20.0 °C to 20.4°C then something is definitely happening with our climate...

From one side we have these extremely rare cold snaps (last time snow settled in downtown Athens for two consecutive years was in the 1860's ) and on the other hand you have these freak heat waves in Athens. Look at what happened last year when for 10 consecutive days the Thiseio WMO station was over 40°C for the first time in its history. In my mind these are worrying signs that the Athenian climate is becoming more and more aggressive. I don't know if tropical plants can survive such extremes for a prolonged period of time. The cold snaps for me are less worrying to be honest ,at least when it comes to the Athens Riviera. The real problem is how aggressive and sustained the summer heat really is in Athens. We have NOA stations with average monthly temperatures that are exactly 30.0°C during the hottest months. Freaking 30.0°C !!! These are Red Sea values and no one could have anticipated this ever happening in the European Continent 10 or 15 years ago.  

Numerous studies on global warming are saying that Athens will be the most affected city in Europe from climate change. Believe me I have read projections for the Athenian climate that are purely dystopian...I believe we need to do something collectively as a country for what is happening to our climate. Appointing a Chief Heat Officer in Athens or a purely decorative Ministry of Climate Change means nothing to me if it is not accompanied by real action...

8 hours ago, Victor G. said:

(Κάποιος είχε παπάγια στην Αττική, κοντά σε Άλιμο/Βουλιαγμένη και πήρε και καρπούς)

[Victor G.]

16 hours ago, Manos33 said:

However don't be fooled by the cold spells the past years in Attica, temperature trends especially the past 10 years in Athens show a dramatic increase. Out of curiosity I calculated the average annual temperature of the Thiseio WMO station in Downtown Athens the past decade (2012-2021) and it works out an amazing 19.74°C. This value would be unheard of 10 years ago for an area in Continental Europe.  On top of that just recently for the first time in the meteorological history of the country HNMS gives a 19.8°C average annual temperature for the Athens Basin WMO stations. Put in the mix the fact that we already have 3 major NOA stations in South Athens recording the past decade average annual temperatures ranging from 20.0 °C to 20.4°C then something is definitely happening with our climate...

I get what you're saying and you're right. Many scientists use the average annual temperature to measure climate change and they are right to do so.
However, I believe the average annual temperature isn't an accurate tool when it comes to gardening (which is my primary focus in this forum).

Take for example Nea Filadelfeia (Greece) and Damascus (Syria). These two places have extremely close avg. annual temperature. However the winters in Damascus are much harder (meaning colder) than in Nea Filadelfia. Damascus compensates for that with its burning summers, able to rise its avg. annual temp. to Nea Filadelfeia levels.

But that means, that you can plant several plants in Nea Filadelfeia that probably wouldn't survive in Damascus.

16 hours ago, Manos33 said:

The real problem is how aggressive and sustained the summer heat really is in Athens. We have NOA stations with average monthly temperatures that are exactly 30.0°C during the hottest months. Freaking 30.0°C !!! These are Red Sea values and no one could have anticipated this ever happening in the European Continent 10 or 15 years ago.  

True, these actually are Red Sea values (I had to look it up, but yeah).
But I don't believe that Athens can compare with these desert cities. The only way that Athens is able to pull off such high mean values is that it is so densely populated than heat cannot escape it.
I don't think that weather stations outside of Athens could rise up to these levels

That said I get your point. And Athens is one hot city in the summer, that we can all agree on

[southathens]

1 hour ago, Victor G. said:

I get what you're saying and you're right. Many scientists use the average annual temperature to measure climate change and they are right to do so.
However, I believe the average annual temperature isn't an accurate tool when it comes to gardening (which is my primary focus in this forum).

I will tell why I think the average annual temperatures are becoming more and more relevant inevitably when it comes to any facet of human activity. If you look closely the past few years the strongest indicator of global warming or climate studies is by far the mean annual temperatures of various locations. Scientists throughout the world use this as the primary indicator of how climate is shifting in one area.  Back when Aiginitis fist managed to systematically record Greece's temperatures through the National Observatory of Athens the mean annual T of downtown Athens was 17.7C. This value of 17.7C was widely quoted in many climate studies and was often mentioned as a source of how stable the Athenian climate has been throughout the centuries. If you read his seminal work ''Greece's climate''  he calculated through various vegetation patterns in Athens that the mean annual temperature in Ancient Athens should indeed have been around 17.7C back then also. 

Fast forward 120 years later and the mean annual of downtown Athens has skyrocketed to 19.74C at least during the past decade making it the warmest WMO station in Continental Europe for the same period. We are talking about a serious shift of 2 full degrees. I doubt this will leave unaffected vegetation in the wider Athens Basin. 

1 hour ago, Victor G. said:

True, these actually are Red Sea values (I had to look it up, but yeah).

Look, I was born in the 80's and I remember very clearly that during the late 90's it would have been unimaginable for any area in Europe to have a mean monthly temperature of 30C+. I remember a mean monthly T of 27.5C was already ''wow'' back then. The pattern of climate change in Athens is undeniable with or without UHI. At current rate by 2100's Athens will be unrecognizable and who knows what kind of plants will be able to survive. No one is saying that Athens will turn into a desert.  In fact the past 10-20 years while mean annual temperatures have risen sharply average annual precipitation has also increased significantly in Athens. Anything north of downtown Athens is seeing huge increase in annual precipitation while anything south of downtown Athens remains stable or shows decrease in annual precipitation. 

This speaks volumes of how much our climate is shifting.  It is basically becoming warmer and wetter in the north and drier but much warmer in the Athens Riviera. Significant storm events are taking place more and more in the Athens Basin coupled with freakish snow storms and hellish non stop heat waves.

Will all that leave vegetation unaffected? I kinda doubt it..

Edited March 17, 2022 by Manos33

[Victor G.]

48 minutes ago, Manos33 said:

Scientists throughout the world use this as the primary indicator of how climate is shifting in one area. 

True. And it is definitely a variable to consider. I'm just saying that my personal point of view is more shifted towards the absolute low temps & cold fronts.
I love tropical plants (especially the ones the give fruit), that's why I'm more concerned about the scenarios that could kill my plants.
And my biggest fear is the cold; not the summer heat waves cause they can handle it and not the drought because I water them as needed.

Of course someone doing climate research would look at all the variables and would probably orient his research according to the avg annual temp.
So it's definitely something to look.

(By the way, there are some rather daring projections that show Athens could turn into a semi-desert, due to rapid decrease of precipitation in the future. Nobody knows at this point if they'll come true of course.)

Now about the +2C change in avg temp:

The climate is definitely becoming warmer and there's absolutely no doubt. Not only in Greece, but everywhere.
But the question is: is it really the only factor that cause the 2C advance? I don't know about that. I'm not a scientist nor have a done any serious research on the subject, but it seems to me that the UHI is much stronger now than it used to be.

I remember my grandparents saying they used to heat their house only when it got really cold (they relied a lot on wood back then, which is more difficult to gather & distribute). Nowadays, literally every house I walk in in the winter (including ours of course) has the heat turned on (at least at night). All those houses and buildings being heated from the inside emit a lot of heat to the neaby environment. And you know how densely some areas of Athens are populated.

Then there's cars; noone can argue that there are a lot more cars on the streets now than in the 80's or 90's. All those engines and fumes heating up the enviroment.

Plus Athens is a city with very little vegetation/parks to absorb heat.

Anyway, I could go on forever, but I'm 100% sure that you know all this stuff (before I learned it).
A massive UHI is being created in Athens (other cities as well) and in my opinion, this definitely contributes to the +2C change is avg temperature.

 

I remember a few years back some scientists stating that we should not measure the temps inside our cities and blame everything on the climate change, but rather take reading from "unaffected" areas outside them.

[southathens]

34 minutes ago, Victor G. said:

A massive UHI is being created in Athens (other cities as well) and in my opinion, this definitely contributes to the +2C change is avg temperature.

True UHI especially during the nights is pronounced in Athens and most major cities. London for example has a significant night UHI as well and many many other cities.  

I suggest you read the article that accompanies the new climate normals for the period 1991-2020 for the Downtown WMO station. You will see that the warming is a complex interplay of many factors.

http://magazine.noa.gr/archives/4446

Also check the mean annuals of stations well outside Athens UHI. For example Anavysos. You will see that it works out a mean annual of over 19.5C the past decade or more. I can't image 20 years ago Anavysos would be able to reach these values. ... So it is not all down to UHI. There are many other factors as well. 

Edited March 17, 2022 by Manos33

[Victor G.]

1 hour ago, Manos33 said:

True UHI especially during the nights is pronounced in Athens and most major cities. London for example has a significant night UHI as well and many many other cities.  

I suggest you read the article that accompanies the new climate normals for the period 1991-2020 for the Downtown WMO station. You will see that the warming is a complex interplay of many factors.

http://magazine.noa.gr/archives/4446

Also check the mean annuals of stations well outside Athens UHI. For example Anavysos. You will see that it works out a mean annual of over 19.5C the past decade or more. I can't image 20 years ago Anavysos would be able to reach these values. ... So it is not all down to UHI. There are many other factors as well. 

Do you have any info regarding precipitation? All projections show that the Medditerranean area will become drier and drier. In the graph it's shown that the last years had more rainfall, but they say it might not be accurate due to an uncommon drought in 1989-1990 but also an uncommon wet period like 2002.

So do we have any information about that?

In my own experience, I believe we are getting less rainfall in the winter, but more rainfall in the summer with some extreme floods.

[southathens]

1 minute ago, Victor G. said:

Do you have any info regarding precipitation? All projections show that the Medditerranean area will become drier and drier. In the graph it's shown that the last years had more rainfall, but they say it might not be accurate due to an uncommon drought in 1989-1990 but also an uncommon wet period like 2002.

So do we have any information about that?

In my own experience, I believe we are getting less rainfall in the winter, but more rainfall in the summer with some extreme floods.

Downtown Athens for the period 1991-2020 has 433mm this is up by almost 60mm from the 1961-1990  period with more rain in the summer indeed but also higher winter precipitation.

 

[southathens]

Its snowing right now in some areas of North Athens and in fact some areas are seeing snow settling on the ground.

Ts are way too high for snow in the Athens Riviera where it is either drizzling or no rain at all. 

Edited March 19, 2022 by Manos33

[southathens]

Here is a camera in the Athens Riviera from Faliro where you can watch live the weather over the next 3-4 days during the cold snap

And here a camera from North Athens where you can watch live. If you are online as I am writing this post you can see the huge contrast. Its snowing heavily in North Athens in contrast with the camera from the Athens Riviera.

 

 

Edited March 20, 2022 by Manos33

[bubba]

Two videos that tell a story…

[Victor G.]

12 minutes ago, bubba said:

Two videos that tell a story…

I hope a snow-less story!

[bubba]

The northside was snowing, the Mediterranean beach, there was nothing! Just how much geographic territory does the Athens area portend?

[southathens]

23 minutes ago, bubba said:

The northside was snowing, the Mediterranean beach, there was nothing! Just how much geographic territory does the Athens area portend?

Here is a photo of the Attica peninsula which is almost entirely occupied by Metropolitan Athens