Fairfield, CA 94534 Frost Dates
94534, near Fairfield, CA: the frost window
Typically, the last spring freeze lands around 01/15, roughly 140 days out. Fall's first freeze usually shows up around 12/14, roughly 336 days after the last spring frost.
Fairfield 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
Fairfield's growing season runs out in roughly 15 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 Fairfield's last frost
01/15 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/16 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/22 and only about 1 year in 10 sees frost after that.
Fairfield against the rest of the dataset
At roughly 336 frost-free days, Fairfield places 2,707 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,230 of 2,555.
Learn more
Two guides worth reading on 94534: local microclimates, on what one yard in Fairfield can differ from the 94534 normal, and zone vs. frost date, on why Zone 9b and Fairfield's frost date answer different questions.