San Ramon, CA 94529 Frost Dates
San Ramon, CA: when does the frost end?
The last spring frost here typically falls around 03/08, about 192 days from today. 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 9b (25 to 30°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.
Why 03/08 isn't a guarantee
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
About 282 days separate San Ramon's last and first frost, putting it 4,752 of 40,283 ZIP codes nationally. Within CA, it ranks 1,750 of 2,555.
Learn more
Before leaning on 94529's figures: local microclimates explains what one yard in San Ramon can differ from the 94529 normal, while zone vs. frost date explains why Zone 9b and San Ramon's frost date answer different questions.