San Ramon, CA 94524 Frost Dates
Frost dates for San Ramon, CA, ZIP 94524
Around 03/08 is the usual last spring frost, about 192 days away. The first fall frost typically arrives around 12/22, about 282 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 Ramon, not a forecast for this year.
What to do before the first frost
Zone 9b around San Ramon has about 17 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.
How much risk comes with planting early here
03/08 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. 04/15 is the safer bet, historically only a 1-in-10 chance of frost that late.
How San Ramon compares
At roughly 282 frost-free days, San Ramon places 4,751 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,749 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 94524 normal.