Cupertino, CA 95129 Frost Dates
Cupertino, CA: when does the frost end?
Around 01/12 is the usual last spring frost, about 137 days away. Fall's first freeze usually shows up around 12/22, roughly 347 days after the last spring frost.
Cupertino 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 Cupertino's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Cupertino's last frost
01/12 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/14 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/20 and only about 1 year in 10 sees frost after that.
Cupertino against the rest of the dataset
At roughly 347 frost-free days, Cupertino places 2,389 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,076 of 2,555.
Learn more
Before leaning on 95129's figures: zone vs. frost date explains why Zone 9b and Cupertino's frost date answer different questions, while the frost range explains how to read the range around Cupertino's dates instead of trusting one.