FrostDateCheck

Hercules, CA 94572 Frost Dates

When can you plant in Hercules, CA?

Zone 9b

Around 02/28 is the usual last spring frost, about 184 days away. The first fall frost typically arrives around 11/22, about 266 frost-free days later.

The USDA Plant Hardiness Zone Map puts Hercules in Zone 9b (25 to 30°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

About 12 weeks of growing season left in Hercules before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.

How much risk comes with planting early here

02/28 is the middle of 30 years of NOAA records, not a promise. Plant by 01/29 and you're betting against frost in roughly 9 years out of 10. 04/05 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Hercules compares

At roughly 266 frost-free days, Hercules places 5,921 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,993 of 2,555.

Learn more

local microclimates covers what one yard in Hercules can differ from the 94572 normal. zone vs. frost date covers why Zone 9b and Hercules's frost date answer different questions.