San Ramon, CA 94575 Frost Dates
When can you plant in San Ramon, CA?
Typically, the last spring freeze lands around 03/08, roughly 192 days out. The first fall frost typically arrives around 12/22, about 282 frost-free days later.
San Ramon sits in USDA Zone 9b (25 to 30°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
About 17 weeks of growing season left in San Ramon before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
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
About 282 days separate San Ramon's last and first frost, putting it 4,754 of 40,283 ZIP codes nationally. Within CA, it ranks 1,752 of 2,555.
Learn more
the frost range covers how to read the range around San Ramon's dates instead of trusting one. local microclimates covers what one yard in San Ramon can differ from the 94575 normal.