As the winters get warmer, even central/historic Jacksonville is trending towards a solid zone 9b.

[Maddox Gardening-youtube]

The past 3 winters have been getting warmer every single year. With tempatures in central Jax never getting below 28 and the beach not going below 30. this warm trend has brought tropical palms in the Jacksonville area. Palms such as foxtails, Areca, and majesty palms are flooding the neighborhood. Many have survived multiple winters and still are looking fresh. Hopefully in the future they will grow big and more people begin experimenting with 10a palms. Here is some evidence I have found throughout central/ historic Jax. It only shows 2 pictures of Areca palms but there are at least one per street.

[kinzyjr]

I made this Hardiness Zone Google Map a little while ago.  It shows the various hardiness zones in the Jacksonville area as you go west to east.  The USDA Zones are split in two (ex. 9a, 9b).  The scheme I used was to split each zone into 5 parts (ex. 9a-1, 9a-2, 9a-b, 9b-1, 9b-2).  Each half zone gets a low and a high, and each zone has a transition a-b zone between "a" and "b".  The map doesn't matter much if we get a record freeze, but it does help identify the milder pockets in an area.  Each of the dots is clickable and brings up a lot of additional information about the weather station at that location.  The USDA uses the average annual low over 30 years for zones (AAL-30), but the map has these averages for 50 and 100 years as well, where applicable.

[Maddox Gardening-youtube]

I kept record of where I was and for some reason, most of the palms were in the southwest Fairfax area. Yet, not close to the river where there as many tropical plants in general. Most of the palms were in this area and really close to highway 17. I don’t know why, but the amount of cement is alot so that would mean a lot of thermal mass. The fumes from the cars could have kept it warmer. It to me was so strange that all of the sudden when you went here there were noticeably more tropical palms

[kinzyjr]

4 minutes ago, Maddox Gardening-youtube said:

I kept record of where I was and for some reason, most of the palms were in the southwest Fairfax area. Yet, not close to the river where there as many tropical plants in general. Most of the palms were in this area and really close to highway 17. I don’t know why, but the amount of cement is alot so that would mean a lot of thermal mass. The fumes from the cars could have kept it warmer. It to me was so strange that all of the sudden when you went here there were noticeably more tropical palms

You're probably familiar with the term urban heat island, which we all shorten to UHI.  In the case of Jacksonville, it does have a relatively strong heat island:

According to UNF, this area is considered to be influenced by the urbanization you mentioned.

https://environment.domains.unf.edu/heatmap/

I think @howfam advised me that I-295 is generally where things start dropping off up that way.  When I draw the next map, perhaps I should use US-17 as a guideline for the 9b-1 cutoff, and I-295 for the 9a-b cutoff?  Depending on the age of the palms you posted and the general WUnderground readings around it, that may make the next map more accurate for this urban area.

[Maddox Gardening-youtube]

Here is a map the blue area is where I found most of the palms, it would technically me a peninsula and has many urban areas around it.

[James B]

Getting colder here in the Inland Empire, California. We just had snow dumped on Mt Baldy in the second week of October. First time ever seeing that this early in the year.

[James B]

For the palm lovers in the Jax area it is pretty cool you get to try out some new species. I remember growing up in the Orlando area and you would never see a Cocos survive due to the winter lows hitting mid 20s. Now more and more are being planted in the Orlando area as getting below 30 is becoming a thing of the past.

[kinzyjr]

20 minutes ago, James B said:

For the palm lovers in the Jax area it is pretty cool you get to try out some new species. I remember growing up in the Orlando area and you would never see a Cocos survive due to the winter lows hitting mid 20s. Now more and more are being planted in the Orlando area as getting below 30 is becoming a thing of the past.

You used to be considered crazy for attempting to grow a queen palm here in the 1980s.  Now, you're crazy if you don't have a few coconuts or crownshaft palms in your yard.  How times change.

All of us are dreading the change back the other way. 😬

[Harry’s Palms]

As @James B mentioned , we had an unusual weather occurrence here in SoCal . I got almost 3” of rain in less than 24hrs . That is highly unusual for mid October , normally it is very dry this time of year , dominated by high pressure systems and low humidity . These systems normally mean warm temps / cool nights and sometimes pretty gusty winds. Last year we got about half our “ normal” rainfall for the season. The previous two years were well above “ normal “ rainfall. I’m not a climatologist so I can’t really speak about anything other than my experience as a gardener , things have changed here . What ever it is , my palms are happy , that’s not to say it’s a good thing . I am watering so much on dry years just to keep them happy . Harry