Santa Rosa, CA 95401 Frost Dates
Frost dates for Santa Rosa, CA, ZIP 95401
Around 02/25 is the usual last spring frost, about 181 days away. The first fall frost typically arrives around 12/01, about 279 frost-free days later.
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 Santa Rosa, not a forecast for this year.
What to do before the first frost
Zone 9a around Santa Rosa has about 14 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
How much risk comes with planting early here
02/25 is the middle of 30 years of NOAA records, not a promise. Plant by 01/21 and you're betting against frost in roughly 9 years out of 10. 03/29 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Santa Rosa compares
At roughly 279 frost-free days, Santa Rosa places 4,849 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,778 of 2,555.
Learn more
local microclimates explains what one yard in Santa Rosa can differ from the 95401 normal, and zone vs. frost date explains why Zone 9a and Santa Rosa's frost date answer different questions.