Clearlake, CA 95457 Frost Dates
Frost dates for Clearlake, CA, ZIP 95457
Around 04/10 is the usual last spring frost, about 225 days away. The first fall frost typically arrives around 11/06, about 209 frost-free days later.
Clearlake 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.
What to do before the first frost
Zone 9a 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.
Why 04/10 isn't a guarantee
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 15,166 of 40,283 ZIP codes nationally. Within CA, it ranks 2,220 of 2,555.
Learn more
zone vs. frost date explains why Zone 9a and Clearlake's frost date answer different questions, and the frost range explains how to read the range around Clearlake's dates instead of trusting one.