Portola, CA 96125 Frost Dates
Frost dates for Portola, CA, ZIP 96125
Around 05/12 is the usual last spring frost, about 257 days away. The first fall frost typically arrives around 10/29, about 167 frost-free days later.
Portola sits in USDA Zone 7a (0 to 5°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 7a around Portola has about 9 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 05/12 isn't a guarantee
05/12 is the middle of 30 years of NOAA records, not a promise. Plant by 04/22 and you're betting against frost in roughly 9 years out of 10. 06/02 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Portola compares
About 167 days separate Portola's last and first frost, putting it 30,024 of 40,283 ZIP codes nationally. Within CA, it ranks 2,407 of 2,555.
Learn more
zone vs. frost date explains why Zone 7a and Portola's frost date answer different questions, and the frost range explains how to read the range around Portola's dates instead of trusting one.