Poway, CA 91976 Frost Dates
Frost dates for Poway, CA, ZIP 91976
Typically, the last spring freeze lands around 03/04, roughly 188 days out. The first fall frost typically arrives around 12/04, about 270 frost-free days later.
The USDA Plant Hardiness Zone Map puts Poway in Zone 10b (35 to 40°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 10b around Poway 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.
Why 03/04 isn't a guarantee
03/04 is the middle of 30 years of NOAA records, not a promise. Plant by 01/29 and you're betting against frost in roughly 9 years out of 10. 04/10 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Poway compares
Poway's growing season runs about 270 days, ranking 5,491 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 1,911 of 2,555.
Learn more
local microclimates explains what one yard in Poway can differ from the 91976 normal, and zone vs. frost date explains why Zone 10b and Poway's frost date answer different questions.