San Fernando, CA 91405 Frost Dates
91405, near San Fernando, CA: the frost window
Typically, the last spring freeze lands around 12/31, roughly 125 days out. Fall's first freeze usually shows up around 12/30, roughly 365 days after the last spring frost.
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 Fernando, not a forecast for this year.
Stretching the season past the first frost
San Fernando's growing season runs out in roughly 18 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around San Fernando's last frost
12/31 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/27 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/09 and only about 1 year in 10 sees frost after that.
San Fernando against the rest of the dataset
San Fernando's growing season runs about 365 days, ranking 1,196 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 517 of 2,555.
Learn more
Two guides worth reading on 91405: the frost range, on how to read the range around San Fernando's dates instead of trusting one, and local microclimates, on what one yard in San Fernando can differ from the 91405 normal.