FrostDateCheck

Moreno Valley, CA 92557 Frost Dates

Frost dates for Moreno Valley, CA, ZIP 92557

Zone 9b

Around 01/27 is the usual last spring frost, about 152 days away. The first fall frost typically arrives around 12/19, about 329 frost-free days later.

The USDA Plant Hardiness Zone Map puts Moreno Valley in Zone 9b (25 to 30°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 9b around Moreno Valley has about 16 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.

Why 01/27 isn't a guarantee

01/27 is the middle of 30 years of NOAA records, not a promise. Plant by 02/28 and you're betting against frost in roughly 9 years out of 10. 12/21 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Moreno Valley compares

About 329 days separate Moreno Valley's last and first frost, putting it 3,070 of 40,283 ZIP codes nationally. Within CA, it ranks 1,323 of 2,555.

Learn more

the frost range explains how to read the range around Moreno Valley's dates instead of trusting one, and local microclimates explains what one yard in Moreno Valley can differ from the 92557 normal.