Nice documentation, and of course if your local conditions/microclimate don't agree with the zone map (is that new USDA map ever going to be released?), go with what you know.

We are rated zone 5b here, but as you can see I've been gardening in zone 6a (or warmer) for quite awhile based on average winter extreme lows for the past decade. All that means is that I can probably count on hardiness long-term for most plants rated to zone 6, especially if sited in well-drained soil. There are many things I've consistently overwintered despite their supposedly being hardy only in warmer zones (Salvia guaranitica, Mirabilis longiflora, Amorphophallus konjac etc.)

Zones are only rough guides - it's fun to take chances and see what happens.

I saw the new USDA map today, says it was released yesterday (1/26). I am now not just 8b on the Arbor day map, I am officially 8b now.......

On the old map and the new one I am shown literally on the border between 7 and 8. I've been tracking my temperatures for the last three winters and so far the lowest temp has been about 11F. This winter I've not seen any temps below 21F.(Zone 9A)

yay global warming lol