Santa Rosa, CA 95403 Frost Dates
When can you plant in Santa Rosa, CA?
The last spring frost here typically falls around 02/25, about 181 days from today. 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
About 14 weeks of growing season left in Santa Rosa before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
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
Santa Rosa's growing season runs about 279 days, ranking 4,851 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 1,780 of 2,555.
Learn more
zone vs. frost date covers why Zone 9a and Santa Rosa's frost date answer different questions. the frost range covers how to read the range around Santa Rosa's dates instead of trusting one.