San Anselmo, CA 94960 Frost Dates
Frost dates for San Anselmo, CA, ZIP 94960
The last spring frost here typically falls around 01/11, about 136 days from today. The first fall frost typically arrives around 12/21, about 349 frost-free days later.
Zone 9b (25 to 30°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 San Anselmo, not a forecast for this year.
What to do before the first frost
Zone 9b around San Anselmo has about 16 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.
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 2,345 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,051 of 2,555.
Learn more
zone vs. frost date explains why Zone 9b and San Anselmo's frost date answer different questions, and the frost range explains how to read the range around San Anselmo's dates instead of trusting one.