San Luis Obispo, CA 93406 Frost Dates
San Luis Obispo, CA: when does the frost end?
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
With roughly 17 weeks until San Luis Obispo's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
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
San Luis Obispo's growing season runs about 349 days, ranking 2,335 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 1,041 of 2,555.
Learn more
Before leaning on 93406's figures: zone vs. frost date explains why Zone 10a and San Luis Obispo's frost date answer different questions, while the frost range explains how to read the range around San Luis Obispo's dates instead of trusting one.