I looked up my town on this website and it says that I'm in zone 9b (25F - 30F average minimum temperature). However, the historical data shows that the temperature never dropped below 41F in the winter. I can also attest from living here for a year that it has never dropped to freezing temperatures. I live a block away from the bay, so the water should keep the weather more temperate. So why does my zone not match the historical weather?
