FrostDateCheck

Belmont, CA 94002 Frost Dates

Frost dates for Belmont, CA, ZIP 94002

Zone 10a

Around 01/17 is the usual last spring frost, about 142 days away. The first fall frost typically arrives around 12/12, about 333 frost-free days later.

The USDA Plant Hardiness Zone Map puts Belmont in Zone 10a (30 to 35°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 10a around Belmont has about 15 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

01/17 is the middle of 30 years of NOAA records, not a promise. Plant by 02/16 and you're betting against frost in roughly 9 years out of 10. 12/20 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Belmont compares

At roughly 333 frost-free days, Belmont places 2,836 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,288 of 2,555.

Learn more

local microclimates explains what one yard in Belmont can differ from the 94002 normal, and zone vs. frost date explains why Zone 10a and Belmont's frost date answer different questions.