San Ramon, CA 94582 Frost Dates
Frost dates for San Ramon, CA, ZIP 94582
Typically, the last spring freeze lands around 02/15, roughly 171 days out. The first fall frost typically arrives around 12/02, about 292 frost-free days later.
The USDA Plant Hardiness Zone Map puts San Ramon 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
Zone 9b around San Ramon 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.
The actual range around San Ramon's last frost
02/15 is the middle of 30 years of NOAA records, not a promise. Plant by 01/12 and you're betting against frost in roughly 9 years out of 10. 03/13 is the safer bet, historically only a 1-in-10 chance of frost that late.
How San Ramon compares
About 292 days separate San Ramon's last and first frost, putting it 4,319 of 40,283 ZIP codes nationally. Within CA, it ranks 1,675 of 2,555.
Learn more
the frost range explains how to read the range around San Ramon's dates instead of trusting one, and local microclimates explains what one yard in San Ramon can differ from the 94582 normal.