Arroyo Grande, CA 93420 Frost Dates
Frost dates for Arroyo Grande, CA, ZIP 93420
Typically, the last spring freeze lands around 02/01, roughly 157 days out. The first fall frost typically arrives around 01/04, about 362 frost-free days later.
Arroyo Grande sits in USDA Zone 9b (25 to 30°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
Zone 9b around Arroyo Grande has about 18 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
02/01 is the middle of 30 years of NOAA records, not a promise. Plant by 03/13 and you're betting against frost in roughly 9 years out of 10. 12/18 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Arroyo Grande compares
Arroyo Grande's growing season runs about 362 days, ranking 2,070 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 956 of 2,555.
Learn more
local microclimates explains what one yard in Arroyo Grande can differ from the 93420 normal, and zone vs. frost date explains why Zone 9b and Arroyo Grande's frost date answer different questions.