Atascadero, CA 93422 Frost Dates
93422, near Atascadero, CA: the frost window
Typically, the last spring freeze lands around 03/15, roughly 199 days out. Fall's first freeze usually shows up around 11/10, roughly 238 days after the last spring frost.
Zone 9a (20 to 25°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 Atascadero, not a forecast for this year.
Stretching the season past the first frost
Atascadero's growing season runs out in roughly 11 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
03/15 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/12 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/13 and only about 1 year in 10 sees frost after that.
Atascadero against the rest of the dataset
At roughly 238 frost-free days, Atascadero places 8,937 of 40,283 ZIP codes in this dataset. Within CA, it ranks 2,125 of 2,555.
Learn more
Two guides worth reading on 93422: local microclimates, on what one yard in Atascadero can differ from the 93422 normal, and zone vs. frost date, on why Zone 9a and Atascadero's frost date answer different questions.