By a tenth of a degree annual mean minimum (50.1 F), Key West is now zone 12(a) for 1991-2020.
Key West is 100 miles from the Florida coast to the north and it's 100 more miles to Bainoa, the coldest town in Cuba where the all time record low of 33 F was recorded (colder than Key West record lows due to landmass and elevation)
"In northwestern Cuba, winter is pleasantly warm, but it's less warm than in the rest of the island. As mentioned, the north-west is the area that, in winter, is more exposed to short and sudden outbreaks of cool air from the United States, which can bring some days a bit cool and windy, and some rain. Occasionally, a particularly cold air mass can arrive, as happened for example in January 1977 (when the temperature dropped to 6 °C or 43 °F in Havana), in January 1981, in February 1996 (when the absolute cold record in Cuba was recorded, 0.6 °C or 33 °F in Bainoa), and in January 2010 (when a low of 4 °C or 39 °F was recorded at Havana airport). In the previous century, it seems that in January 1857 it even snowed in Cárdenas, and frosts ruined the crops."
Key West is basically an ultra tropical Caribbean island (zone 12+). Miami/Beach/FTL proper (zone 11) is hard tropical with extremely rare frost, but both fall short of hypertropical zone 13 places that have never been below 50, or those most equatorial islands (Palmyra Atoll, Nauru) or the extreme hot deserts (Danakill/Dallol where it's humid without rain) that have rarely or never been below room temperature (zone 14)
The line is drawn nearly north-south here vs the classic FL NNW because both of these locations are to the SSW:
Nicest Aceolorrhaphe wrightii I have noticed, all survived but this is the only one I’ve seen where the existing trunks survived, even a big one on the island died to the ground and started regrowing. There were only ever a handful around to begin with that I’m aware of.
So being the palm dweeb that I am, last night I was researching the lowest annual temperatures for Baltimore (my hometown) and I realized that the lowest temperatures were recorded at BWI airport. The airport is cooler than my location and I was curious what the same temperatures were in areas closer to me. So on the days where the lowest temperatures were recorded, I searched the temperatures at the weather stations closest to me and these were my findings for the past 20 years:
20 year Average: 11.8° Zone 8a
This change to zone 8 is reflected in the Arbor Day Foundation Hardiness zone map. Despite some zone 7 winters, the majority of winters are zone 8 here (which excites me tremendously!!!!!!)
I just thought this was interesting for those curious about microclimates since I live in one generated by the Baltimore metro on one side and the Chesapeake Bay on the other.
Does this hardiness zone map seem about right?
I read that the Musa Bajool Banana is native to central China, is this true? The range that it is said to be native to is not in the tropics (or at least this part), so wouldn't they die here (look at image of where Wikipedia says they are native) due to frosts? Or do they just naturally grow like that? I am a little confused.