FrostDateCheck

Danville, CA 94526 Frost Dates

94526, near Danville, CA: the frost window

Zone 9b

Around 03/08 is the usual last spring frost, about 192 days away. Fall's first freeze usually shows up around 12/22, roughly 282 days after the last spring frost.

The USDA Plant Hardiness Zone Map puts Danville in Zone 9b (25 to 30°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.

Stretching the season past the first frost

Danville's growing season runs out in roughly 17 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.

Why 03/08 isn't a guarantee

03/08 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/12 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/15 and only about 1 year in 10 sees frost after that.

Danville against the rest of the dataset

Danville's growing season runs about 282 days, ranking 4,763 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 1,761 of 2,555.

Learn more

Two guides worth reading on 94526: local microclimates, on what one yard in Danville can differ from the 94526 normal, and zone vs. frost date, on why Zone 9b and Danville's frost date answer different questions.