Poway, CA 92159 Frost Dates
Frost dates for Poway, CA, ZIP 92159
Around 03/04 is the usual last spring frost, about 188 days away. 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.
How much risk comes with planting early here
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
At roughly 270 frost-free days, Poway places 5,529 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,949 of 2,555.
Learn more
zone vs. frost date explains why Zone 10b and Poway's frost date answer different questions, and the frost range explains how to read the range around Poway's dates instead of trusting one.