Plant hardiness map updated and newly released

[swincher]

My prediction was true!

Seattle should be moving to zone 9a in the next update

In the USDA map based on data as of 1990, Seattle was placed in zone 8a, meaning the 30-year average of the annual minimum temperature was 10-15°F at that point. The latest USDA growing zone maps were based on 2012 data, when Seattle’s number was in the upper teens and we were moved to zone 8b. Well I don’t know when the USDA will be updating their maps next, but at least for the official Seattle weather station, our 30-year average is now 21.2°F, which would put us in 9a if the map was re-dra…

There’s a whole pocket of 9a around Seattle now, this was all 8b in the 2012 map: