San Leandro, CA 94603 Frost Dates
Frost dates for San Leandro, CA, ZIP 94603
The last spring frost here typically falls around 01/07, about 132 days from today. The first fall frost typically arrives around 12/23, about 356 frost-free days later.
Zone 10a (30 to 35°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 San Leandro, not a forecast for this year.
What to do before the first frost
Zone 10a around San Leandro has about 17 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 01/07 isn't a guarantee
01/07 is the middle of 30 years of NOAA records, not a promise. Plant by 02/08 and you're betting against frost in roughly 9 years out of 10. 12/13 is the safer bet, historically only a 1-in-10 chance of frost that late.
How San Leandro compares
At roughly 356 frost-free days, San Leandro places 2,101 of 40,283 ZIP codes in this dataset. Within CA, it ranks 965 of 2,555.
Learn more
zone vs. frost date explains why Zone 10a and San Leandro's frost date answer different questions, and the frost range explains how to read the range around San Leandro's dates instead of trusting one.