Irvine, CA 92628 Frost Dates
Frost dates for Irvine, CA, ZIP 92628
Around 01/05 is the usual last spring frost, about 130 days away. The first fall frost typically arrives around 12/25, about 365 frost-free days later.
Irvine sits in USDA Zone 10b (35 to 40°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 10b around Irvine 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
01/05 is the middle of 30 years of NOAA records, not a promise. Plant by 02/02 and you're betting against frost in roughly 9 years out of 10. 12/14 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Irvine compares
Irvine's growing season runs about 365 days, ranking 257 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 52 of 2,555.
Learn more
zone vs. frost date explains why Zone 10b and Irvine's frost date answer different questions, and the frost range explains how to read the range around Irvine's dates instead of trusting one.