Windsor, CA 95446 Frost Dates
When can you plant in Windsor, CA?
Around 01/29 is the usual last spring frost, about 154 days away. The first fall frost typically arrives around 12/30, about 347 frost-free days later.
The USDA Plant Hardiness Zone Map puts Windsor in Zone 9b (25 to 30°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 18 weeks of growing season left in Windsor before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 01/29 isn't a guarantee
01/29 is the middle of 30 years of NOAA records, not a promise. Plant by 03/17 and you're betting against frost in roughly 9 years out of 10. 12/17 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Windsor compares
At roughly 347 frost-free days, Windsor places 2,392 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,079 of 2,555.
Learn more
local microclimates covers what one yard in Windsor can differ from the 95446 normal. zone vs. frost date covers why Zone 9b and Windsor's frost date answer different questions.