Santa Rosa, CA 95406 Frost Dates
Santa Rosa, CA: when does the frost end?
Typically, the last spring freeze lands around 02/25, roughly 181 days out. Fall's first freeze usually shows up around 12/01, roughly 279 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 Santa Rosa, not a forecast for this year.
Stretching the season past the first frost
With roughly 14 weeks until Santa Rosa's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Santa Rosa's last frost
02/25 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/21 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 03/29 and only about 1 year in 10 sees frost after that.
Santa Rosa against the rest of the dataset
About 279 days separate Santa Rosa's last and first frost, putting it 4,854 of 40,283 ZIP codes nationally. Within CA, it ranks 1,783 of 2,555.
Learn more
Before leaning on 95406's figures: the frost range explains how to read the range around Santa Rosa's dates instead of trusting one, while local microclimates explains what one yard in Santa Rosa can differ from the 95406 normal.