San Jose, CA 95122 Frost Dates
95122, near San Jose, CA: the frost window
Typically, the last spring freeze lands around 01/02, roughly 127 days out. Fall's first freeze usually shows up around 12/25, roughly 362 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts San Jose 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
San Jose'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.
How much risk comes with planting early here
01/02 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/23 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/14 and only about 1 year in 10 sees frost after that.
San Jose against the rest of the dataset
At roughly 362 frost-free days, San Jose places 2,052 of 40,283 ZIP codes in this dataset. Within CA, it ranks 938 of 2,555.
Learn more
Two guides worth reading on 95122: zone vs. frost date, on why Zone 9b and San Jose's frost date answer different questions, and the frost range, on how to read the range around San Jose's dates instead of trusting one.