San Luis Obispo, CA 93448 Frost Dates
93448, near San Luis Obispo, CA: the frost window
The last spring frost here typically falls around 01/16, about 141 days from today. Fall's first freeze usually shows up around 12/25, roughly 349 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 Luis Obispo, not a forecast for this year.
Stretching the season past the first frost
San Luis Obispo's growing season runs out in roughly 17 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
01/16 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/26 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/11 and only about 1 year in 10 sees frost after that.
San Luis Obispo against the rest of the dataset
At roughly 349 frost-free days, San Luis Obispo places 2,341 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,047 of 2,555.
Learn more
Two guides worth reading on 93448: zone vs. frost date, on why Zone 10a and San Luis Obispo's frost date answer different questions, and the frost range, on how to read the range around San Luis Obispo's dates instead of trusting one.