Lathrop, CA 95330 Frost Dates
Frost dates for Lathrop, CA, ZIP 95330
Typically, the last spring freeze lands around 02/06, roughly 162 days out. The first fall frost typically arrives around 12/01, about 304 frost-free days later.
Zone 9b (25 to 30°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Lathrop, not a forecast for this year.
What to do before the first frost
Zone 9b around Lathrop has about 14 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
02/06 is the middle of 30 years of NOAA records, not a promise. Plant by 02/28 and you're betting against frost in roughly 9 years out of 10. 12/31 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Lathrop compares
About 304 days separate Lathrop's last and first frost, putting it 3,762 of 40,283 ZIP codes nationally. Within CA, it ranks 1,527 of 2,555.
Learn more
local microclimates explains what one yard in Lathrop can differ from the 95330 normal, and zone vs. frost date explains why Zone 9b and Lathrop's frost date answer different questions.