FrostDateCheck

Atwater, CA 93661 Frost Dates

Atwater, CA: when does the frost end?

Zone 9a

Around 02/26 is the usual last spring frost, about 182 days away. Fall's first freeze usually shows up around 11/25, roughly 273 days after the last spring frost.

Atwater 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.

Stretching the season past the first frost

With roughly 13 weeks until Atwater's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.

How much risk comes with planting early here

02/26 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/20 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/01 and only about 1 year in 10 sees frost after that.

Atwater against the rest of the dataset

About 273 days separate Atwater's last and first frost, putting it 5,187 of 40,283 ZIP codes nationally. Within CA, it ranks 1,826 of 2,555.

Learn more

Before leaning on 93661's figures: the frost range explains how to read the range around Atwater's dates instead of trusting one, while local microclimates explains what one yard in Atwater can differ from the 93661 normal.