Windsor, CA 95492 Frost Dates
Windsor, CA: when does the frost end?
Around 03/02 is the usual last spring frost, about 186 days away. Fall's first freeze usually shows up around 11/20, roughly 262 days after the last spring frost.
Zone 9a (20 to 25°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Windsor, not a forecast for this year.
Stretching the season past the first frost
With roughly 12 weeks until Windsor's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 03/02 isn't a guarantee
03/02 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/27 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/02 and only about 1 year in 10 sees frost after that.
Windsor against the rest of the dataset
At roughly 262 frost-free days, Windsor places 6,204 of 40,283 ZIP codes in this dataset. Within CA, it ranks 2,026 of 2,555.
Learn more
Before leaning on 95492's figures: zone vs. frost date explains why Zone 9a and Windsor's frost date answer different questions, while the frost range explains how to read the range around Windsor's dates instead of trusting one.