Sonora, CA 95305 Frost Dates
Frost dates for Sonora, CA, ZIP 95305
The last spring frost here typically falls around 04/22, about 237 days from today. The first fall frost typically arrives around 11/02, about 192 frost-free days later.
Zone 9b (25 to 30°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 Sonora, not a forecast for this year.
What to do before the first frost
Zone 9b around Sonora has about 9 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
How much risk comes with planting early here
04/22 is the middle of 30 years of NOAA records, not a promise. Plant by 04/05 and you're betting against frost in roughly 9 years out of 10. 05/14 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Sonora compares
Sonora's growing season runs about 192 days, ranking 20,287 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 2,301 of 2,555.
Learn more
the frost range explains how to read the range around Sonora's dates instead of trusting one, and local microclimates explains what one yard in Sonora can differ from the 95305 normal.