Palo Alto, CA 94305 Frost Dates
Frost dates for Palo Alto, CA, ZIP 94305
The last spring frost here typically falls around 02/01, about 157 days from today. The first fall frost typically arrives around 12/07, about 310 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 Palo Alto, not a forecast for this year.
What to do before the first frost
Zone 9b around Palo Alto 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.
The actual range around Palo Alto's last frost
02/01 is the middle of 30 years of NOAA records, not a promise. Plant by 03/04 and you're betting against frost in roughly 9 years out of 10. 12/28 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Palo Alto compares
At roughly 310 frost-free days, Palo Alto places 3,550 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,470 of 2,555.
Learn more
the frost range explains how to read the range around Palo Alto's dates instead of trusting one, and local microclimates explains what one yard in Palo Alto can differ from the 94305 normal.