San Luis Obispo, CA 93483 Frost Dates
Frost dates for San Luis Obispo, CA, ZIP 93483
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.
The USDA Plant Hardiness Zone Map puts San Luis Obispo in Zone 10a (30 to 35°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 10a around San Luis Obispo has about 17 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.
How much risk comes with planting early here
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
San Luis Obispo's growing season runs about 349 days, ranking 2,342 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 1,048 of 2,555.
Learn more
local microclimates explains what one yard in San Luis Obispo can differ from the 93483 normal, and zone vs. frost date explains why Zone 10a and San Luis Obispo's frost date answer different questions.