FrostDateCheck

Clearlake, CA 95426 Frost Dates

Frost dates for Clearlake, CA, ZIP 95426

Zone 9b

Typically, the last spring freeze lands around 04/10, roughly 225 days out. The first fall frost typically arrives around 11/06, about 209 frost-free days later.

Clearlake sits in USDA Zone 9b (25 to 30°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.

What to do before the first frost

Zone 9b around Clearlake has about 10 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

04/10 is the middle of 30 years of NOAA records, not a promise. Plant by 03/24 and you're betting against frost in roughly 9 years out of 10. 04/30 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Clearlake compares

About 209 days separate Clearlake's last and first frost, putting it 15,163 of 40,283 ZIP codes nationally. Within CA, it ranks 2,217 of 2,555.

Learn more

local microclimates explains what one yard in Clearlake can differ from the 95426 normal, and zone vs. frost date explains why Zone 9b and Clearlake's frost date answer different questions.