Fairfax, CA 94966 Frost Dates
94966, near Fairfax, CA: the frost window
Typically, the last spring freeze lands around 01/11, roughly 136 days out. Fall's first freeze usually shows up around 12/21, roughly 349 days after the last spring frost.
Fairfax sits in USDA Zone 10a (30 to 35°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
Fairfax's growing season runs out in roughly 16 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
01/11 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/25 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.
Fairfax against the rest of the dataset
Fairfax's growing season runs about 349 days, ranking 2,357 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 1,063 of 2,555.
Learn more
Two guides worth reading on 94966: zone vs. frost date, on why Zone 10a and Fairfax's frost date answer different questions, and the frost range, on how to read the range around Fairfax's dates instead of trusting one.