San Ramon, CA 94820 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.
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.
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.
The actual range around San Ramon's last frost
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
San Ramon's growing season runs about 282 days, ranking 4,760 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 1,758 of 2,555.
Learn more
Before leaning on 94820's figures: zone vs. frost date explains why Zone 9b and San Ramon's frost date answer different questions, while the frost range explains how to read the range around San Ramon's dates instead of trusting one.