FrostDateCheck

Sonora, CA 95310 Frost Dates

When can you plant in Sonora, CA?

Zone 9a

The last spring frost here typically falls around 02/20, about 176 days from today. The first fall frost typically arrives around 12/11, about 290 frost-free days later.

Sonora sits in USDA Zone 9a (20 to 25°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.

What to do before the first frost

About 15 weeks of growing season left in Sonora before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.

The actual range around Sonora's last frost

02/20 is the middle of 30 years of NOAA records, not a promise. Plant by 01/10 and you're betting against frost in roughly 9 years out of 10. 04/07 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Sonora compares

Sonora's growing season runs about 290 days, ranking 4,510 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 1,700 of 2,555.

Learn more

the frost range covers how to read the range around Sonora's dates instead of trusting one. local microclimates covers what one yard in Sonora can differ from the 95310 normal.