San Anselmo, CA 94957 Frost Dates
When can you plant in San Anselmo, CA?
Typically, the last spring freeze lands around 01/11, roughly 136 days out. The first fall frost typically arrives around 12/21, about 349 frost-free days later.
The USDA Plant Hardiness Zone Map puts San Anselmo 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 16 weeks of growing season left in San Anselmo before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around San Anselmo's last frost
01/11 is the middle of 30 years of NOAA records, not a promise. Plant by 02/25 and you're betting against frost in roughly 9 years out of 10. 12/14 is the safer bet, historically only a 1-in-10 chance of frost that late.
How San Anselmo compares
At roughly 349 frost-free days, San Anselmo places 2,344 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,050 of 2,555.
Learn more
zone vs. frost date covers why Zone 9b and San Anselmo's frost date answer different questions. the frost range covers how to read the range around San Anselmo's dates instead of trusting one.