Irvine, CA 90633 Frost Dates
When can you plant in Irvine, CA?
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.
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 Irvine, not a forecast for this year.
What to do before the first frost
About 17 weeks of growing season left in Irvine before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 01/05 isn't a guarantee
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 244 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 39 of 2,555.
Learn more
zone vs. frost date covers why Zone 10a and Irvine's frost date answer different questions. the frost range covers how to read the range around Irvine's dates instead of trusting one.