Australian major city rainfall comparisons

[Tyrone]

I did a bit of research and thought I'd rank Australian major cities from highest to lowest based on average annual rainfall.

Darwin 1734.2mm

Sydney 1212.5mm

Brisbane 997.6mm

Perth 773.9mm

Melbourne 649.8mm

Hobart 616.7mm

Adelaide 546mm

Alice Springs 286.7mm

To put an international perspective on it

Darwin 1734.2mm

Miami 1420mm

New York 1262.1mm

Auckland 1240mm

Buenos Aires 1214.6mm

Sydney 1212.5mm

Brisbane 997.6mm

Rome 874.7mm

Perth 773.9mm

Melbourne 649.8mm

Paris 649.6mm

Cairo 627.4mm

Hobart 616.7mm

London 601.5mm

Berlin 571mm

San Francisco 565.9mm

Jerusalem 554.1mm

Adelaide 546mm

Athens 414.1mm

Los Angeles 384.6mm

Alice Springs 286.7mm

San Diego 273.6mm

Thought some may find this interesting.

Tyrone

[Tropicgardener]

Geez San Diego is a bloody dry joint !!!

[ariscott]

Interesting.... we should really include Jakarta, Bangkok, Manila and South American capitals.... then Darwin will be down on the list.

Regards, Ari

[Tyrone]

Interesting.... we should really include Jakarta, Bangkok, Manila and South American capitals.... then Darwin will be down on the list.

Regards, Ari

I was thinking of doing that. I may include some more cities including equatorial climate cities and expand the list.

What prompted me to do this, is that over here in the west of Oz (particularly Perth and the SW) we are constantly bombarded with the false belief that we are in a very dry part of the Earth. When you compare Perth with other major population centres around the globe it basically isn't one of the driest. As far as Australian capitals are concerned it's the 4th wettest. Out of the list I compiled below it came 9th out of 22 selected cities. It's wetter than "rainy" Melbourne, Paris, Cairo, Hobart, London, Berlin, and San Francisco. But the figure I used was from the airport where no dams are. Perth dams are up at elevation in the hills where the average annual rainfall figures are these, Dwellingup 1237.9mm, Karnet 1151.2mm, Bickley 1089.5mm, Kalamunda 1065.9mm. The Dwellingup figure (1237.9mm) is higher than Sydney's Observatory Hill site (1212.5mm) and almost as high as Auckland's rainfall (1240mm).

From a water supply point of view the population density is a large consideration. Here in Perth it's low with about 1.7 million inhabitants (2 million across the state). Whereas London gets by with less rainfall but a huge population in comparison. I think a case in point is California. The population of California is larger than Australia combined, yet they get by on San Francisco 565.9mm, LA 384.6mm, and San Diego 273.6mm. San Diego's figure is less than Alice Springs 286.7mm which is smack bang in the middle of the Australian desert.

Here in Perth we get over 4 times the annual rainfall in our dams as San Diego receives with only a fraction of the population, yet we are still in trouble.

To make it clear I have nothing against water saving measures. Wasting water is wrong. But on the one hand we are being told to save water, yet the water tank rebate system was removed for example. The infrastructure of this place clearly can't hold up, yet they keep planning for massive expansion and growth, without planning for any real improvement in our water supply. It wouldn't matter if we got years of really wet weather now, as the population would just suck the dams dry every year. In the meantime we're being force fed this message that we live in one of the driest places on Earth. Yet we can take a drive up into the hills and see all the forests growing, which wouldn't be there if we really were in a desert as they make out.

Best regards

Tyrone

[Daryl]

Good points Tyrone. As you mentioned there are nearby areas to each of the major Australian cities that receive much higher rainfall. The other thing you have to consider is evaporation rate.

The Californians can chime in here, but isn't a lot of their water sourced from the mountains where rainfall/snow etc provides a lot of this precious resource?

The other factor is the distribution of rainfall, and the reason that Melbourne is thought of as 'rainy', the same as London...their daily totals may not be high, but it does rain on a lot of days.

Daryl

[Tyrone]

Good points Tyrone. As you mentioned there are nearby areas to each of the major Australian cities that receive much higher rainfall. The other thing you have to consider is evaporation rate.

The Californians can chime in here, but isn't a lot of their water sourced from the mountains where rainfall/snow etc provides a lot of this precious resource?

The other factor is the distribution of rainfall, and the reason that Melbourne is thought of as 'rainy', the same as London...their daily totals may not be high, but it does rain on a lot of days.

Daryl

Yes, that is right. The catchment areas around Brisbane would be closer to 2000mm than 1000mm. Same with Sydney. But Perth and the SW of the country are far from desert regions as many people have been led to believe. I was down on the south coast during the week and it was wet and miserable down there, with flooded paddocks and drains etc, but very very green. Those same areas stay wet and green all year.

I would love to know where California gets its water from. No doubt the mountains which are very high compared to ours would collect much more precipitation than the lower altitudes. But their population over there is vast compared to Australia, so they're keeping a lot of people alive over there successfully.

Evaporation rate is a very real factor to consider. Perth in summer can have evap rates of 12-13mm per day, but no real summer rainfall making irrigation a real necessity for any sort of garden here. London with less annual rainfall and no real dry season and lower evaporation rates will feel like a rainier city compared to Perth, and require little if any irrigation for a garden to survive.

The challenge is to collect the rain when it falls and apply it when evap rates are highest. A complete irrigation ban here this summer would destroy almost all gardens and the gardening industry.

Best regards

Tyrone

[Jubaea]

I don't think that this was mentioned but another thing to take into consideration is what type of soil you have. This is important for both water storage, trasportation, and irrigation.

The area in California that I am in has clay soil which holds moisture better than the sand that is in Perth.

As for the water sources much of it does not originate in Southern California. Northern California gets much more rain and snow in the higher elevations than does So Cal. This and even water from the Colorado river is channeled to So Cal. Snowmelt is an imporatant water source for much of the South Western USA. It provides water in the dry months when no rain falls for months at a time. There is still quite a bit of snow in the higher elevations in the Sierra Nevada mountains after above average snowfall.

[peachy]

Having just spent 10 years on water restrictions, the last 2 being a total ban on watering of any kind, I was almost becoming a water use nazi. However in light of recent events, the dams filling up and being released in a time of record rainfall causing major flooding, I believe now that more dams are essential, especially in the city areas where the population densities are very high. I firmly believe that all new houses should have tanks, be they underground or above ground, before they are allowed to be occupied.

Peachy

Edited July 11, 2011 by peachy

[Tyrone]

Peachy, I think you've touched on a good point that Australias climate is extremely variable from one year/decade to the next. During good years we can become complacent and think the good times won't end. During the bad times, everyone panics, restrictions are imposed, in extreme cases people are scared to even flush the toilet, and we're meant to feel that it's our fault and we have to make adjustments, which is true to a point, but there is only so much you can do before your choices and standards of living start to drop off. Methods should be imposed during the good times to ride out the bad times which will with 100% certainty return. We should not be forced to plant endemic natives into our gardens. I really don't want a garden of Anigozanthos, Callistemons and Banksias, which still need irrigation to establish if planted outside the winter period here, provided we even get the winter rains.

Agree with the compulsory water tanks ( I need to get one here) but I can't understand for example why the state government removed it's water tank rebate scheme (except for along the south coast where they need it the least).

Dylan, agree about soil type. Here on the coastal plain it is sand (where most people live). In the catchments areas it is gravelly clay like the majority of Australia. From a horticultural point of view, upgrading the sand with tons of organics should upgrade the soils water holding capacity and allow a reduction in irrigation for established plants. Interesting that water needs to piped in where you live. I think that's the only real answer over here.

Best regards

Tyrone

[Mike in Nelson]

Rainfall/climate is definitely a perception thing. There are alot of UK immigrants living here in Nelson and they often comment on how it "rains all the time back in the UK" but in actual fact Nelson gets around twice the annual rainfall as the UK. We must get rain here in shorter, heavier bursts with more sunshine in between.

[Tyrone]

Rainfall/climate is definitely a perception thing. There are alot of UK immigrants living here in Nelson and they often comment on how it "rains all the time back in the UK" but in actual fact Nelson gets around twice the annual rainfall as the UK. We must get rain here in shorter, heavier bursts with more sunshine in between.

I think you're right. English rain is sort of without any purpose. I remember seeing the finest rain I've ever seen during summer in Bournemouth on the south coast of the UK. It was so fine you could barely see it. It would sort of drift on the slightest breeze and come underneath covered areas and slowly make you feel damp. You'd be standing there talking to someone for a while and go, "wait a minute, why am I wet, I'm under a roof for crying out loud" Really weird, like living in a cloud. Here when it rains you know it's raining, you get drenched, and then the sun comes out. That sort of wispy weightless stuff wouldn't even register in a rain gauge. I'd never seen anything like it before.

Best regards

Tyrone