Sierra Madre, CA 91024 Frost Dates
Frost dates for Sierra Madre, CA, ZIP 91024
Typically, the last spring freeze lands around 01/08, roughly 133 days out. The first fall frost typically arrives around 01/07, about 365 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 Sierra Madre, not a forecast for this year.
What to do before the first frost
Zone 10a around Sierra Madre has about 19 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 01/08 isn't a guarantee
01/08 is the middle of 30 years of NOAA records, not a promise. Plant by 02/17 and you're betting against frost in roughly 9 years out of 10. 12/20 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Sierra Madre compares
At roughly 365 frost-free days, Sierra Madre places 1,727 of 40,283 ZIP codes in this dataset. Within CA, it ranks 848 of 2,555.
Learn more
the frost range explains how to read the range around Sierra Madre's dates instead of trusting one, and local microclimates explains what one yard in Sierra Madre can differ from the 91024 normal.