San Ramon, CA 94802 Frost Dates
San Ramon, CA: when does the frost end?
Typically, the last spring freeze lands around 03/08, roughly 192 days out. Fall's first freeze usually shows up around 12/22, roughly 282 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts San Ramon in Zone 10a (30 to 35°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 17 weeks until San Ramon's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
03/08 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/12 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/15 and only about 1 year in 10 sees frost after that.
San Ramon against the rest of the dataset
At roughly 282 frost-free days, San Ramon places 4,757 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,755 of 2,555.
Learn more
Before leaning on 94802's figures: the frost range explains how to read the range around San Ramon's dates instead of trusting one, while local microclimates explains what one yard in San Ramon can differ from the 94802 normal.