Cupertino, CA 94087 Frost Dates
94087, near Cupertino, CA: the frost window
Around 01/06 is the usual last spring frost, about 131 days away. Fall's first freeze usually shows up around 12/23, roughly 353 days after the last spring frost.
Zone 9b (25 to 30°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Cupertino, not a forecast for this year.
Stretching the season past the first frost
Cupertino's growing season runs out in roughly 17 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Cupertino's last frost
01/06 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/04 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/16 and only about 1 year in 10 sees frost after that.
Cupertino against the rest of the dataset
At roughly 353 frost-free days, Cupertino places 2,219 of 40,283 ZIP codes in this dataset. Within CA, it ranks 999 of 2,555.
Learn more
Two guides worth reading on 94087: local microclimates, on what one yard in Cupertino can differ from the 94087 normal, and zone vs. frost date, on why Zone 9b and Cupertino's frost date answer different questions.