Well...duno what happened to my post from last nite.......not here...???? But had said I didn't know.....so much appreciated for the heads up Not all of us are as in tune as to what's going on. And in my case, I already sit right on the cusp of 7a & b...it may affect me a bit. Cant find pic of VA map I can zoom in to see yet). But if nothing else..it WILL affect shipping time for mail order in some areas. So thanks again If this post has funky typos....its cuz GW. site and tablets don't get along too well I'm guessing.......or maybe just me with learning curve...lol But can't bear to go into house. On porch using it, enjoying first gentle spring rain....yeahhhhhhhhhh!!!!!

The colors on this new map are very similar. The USDA should have used clearly different colors for the different zones, so there would be no confusion. I guess they wanted it to be color coordinated for eye appeal, which is silly, because I'm not planting the map. Anyway, I am looking at Tennessee right now. Franklin County is mostly zone 7a, but there is a long blotch of zone 7b running from the SW corner up towards the NE corner of the county. Shelby County is really hard to read. It is all zone 7b except for part of the extreme SW corner, which is zone 8a. That is the only zone 8a I see in the entire state of TN, and the city name "Memphis" is partially covering it. I have fairly young eyes, but if an older person (no disrespect intended) looked at this new map, I'm sure it could be very hard to tell these colors apart. Oh well, what do you expect? The Federal Government made it. lol

You need to remove the period (full stop!) at the end for that URL to work. It really isn't that high rez. anyhow. But also, even more than the USDA hardiness map this AHS heat map is of very limited utility. Number of days over 86F is essentially meaningless for a lot of plants. Right off the bat, it would have made more sense to plot the average summer nighttime dewpoint temperature. At Sonoma Horticultural Nursery in - surprise surprise - Sonoma County CA, they can grow the Himalayan cinnabarina series Rhododendrons. Or the hardy big leafs like R. rex. At Rarefind in NJ, you cannot. Even the ones that would be winter hardy there. The two locations probably have a similar # of days above 86F, but their summer climates are hugely different as are their winter climates. The cool nights and lower dewpoints in Sonoma County make all the difference.

These maps are just guidelines. Where i live it says zone 4b which is about right (MOST OF THE TIME)... The problem is when you go back and look at records for here. The coldest ever reading in town is -43F. That isn't any zone 4b if that would happen again! All kinds of records in the -30F's... If you want to see what your all time record lows for any date are, the NWS has something called NOWData.. Its way cool and if you need help let me know. Its usually only a few cities/towns, but it gives a good idea of what you "COULD" expect any given winter. And on that note, next winter is going to be record cold :)