Atwater, CA 95341 Frost Dates
Frost dates for Atwater, CA, ZIP 95341
The last spring frost here typically falls around 02/26, about 182 days from today. The first fall frost typically arrives around 11/25, about 273 frost-free days later.
The USDA Plant Hardiness Zone Map puts Atwater in Zone 9a (20 to 25°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 9a around Atwater has about 13 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
02/26 is the middle of 30 years of NOAA records, not a promise. Plant by 01/20 and you're betting against frost in roughly 9 years out of 10. 04/01 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Atwater compares
At roughly 273 frost-free days, Atwater places 5,188 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,827 of 2,555.
Learn more
local microclimates explains what one yard in Atwater can differ from the 95341 normal, and zone vs. frost date explains why Zone 9a and Atwater's frost date answer different questions.