FrostDateCheck

Sonora, CA 95379 Frost Dates

95379, near Sonora, CA: the frost window

Zone 8b

The last spring frost here typically falls around 04/22, about 237 days from today. Fall's first freeze usually shows up around 11/02, roughly 192 days after the last spring frost.

Sonora sits in USDA Zone 8b (15 to 20°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

Sonora's growing season runs out in roughly 9 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.

Why 04/22 isn't a guarantee

04/22 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/05 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/14 and only about 1 year in 10 sees frost after that.

Sonora against the rest of the dataset

About 192 days separate Sonora's last and first frost, putting it 20,291 of 40,283 ZIP codes nationally. Within CA, it ranks 2,305 of 2,555.

Learn more

Two guides worth reading on 95379: local microclimates, on what one yard in Sonora can differ from the 95379 normal, and zone vs. frost date, on why Zone 8b and Sonora's frost date answer different questions.