Clearlake, CA 95423 Frost Dates
Clearlake, CA: when does the frost end?
Around 04/10 is the usual last spring frost, about 225 days away. Fall's first freeze usually shows up around 11/06, roughly 209 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Clearlake in Zone 9a (20 to 25°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
With roughly 10 weeks until Clearlake's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Clearlake's last frost
04/10 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/24 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/30 and only about 1 year in 10 sees frost after that.
Clearlake against the rest of the dataset
Clearlake's growing season runs about 209 days, ranking 15,161 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 2,215 of 2,555.
Learn more
Before leaning on 95423's figures: zone vs. frost date explains why Zone 9a and Clearlake's frost date answer different questions, while the frost range explains how to read the range around Clearlake's dates instead of trusting one.