FrostDateCheck

San Luis Obispo, CA 93412 Frost Dates

When can you plant in San Luis Obispo, CA?

Zone 10a

Around 01/16 is the usual last spring frost, about 141 days away. The first fall frost typically arrives around 12/25, about 349 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 Luis Obispo, not a forecast for this year.

What to do before the first frost

About 17 weeks of growing season left in San Luis Obispo before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.

The actual range around San Luis Obispo's last frost

01/16 is the middle of 30 years of NOAA records, not a promise. Plant by 02/26 and you're betting against frost in roughly 9 years out of 10. 12/11 is the safer bet, historically only a 1-in-10 chance of frost that late.

How San Luis Obispo compares

About 349 days separate San Luis Obispo's last and first frost, putting it 2,339 of 40,283 ZIP codes nationally. Within CA, it ranks 1,045 of 2,555.

Learn more

the frost range covers how to read the range around San Luis Obispo's dates instead of trusting one. local microclimates covers what one yard in San Luis Obispo can differ from the 93412 normal.