Chula Vista, CA 91913 Frost Dates
Frost dates for Chula Vista, CA, ZIP 91913
Around 01/06 is the usual last spring frost, about 131 days away. The first fall frost typically arrives around 12/31, about 365 frost-free days later.
Zone 10b (35 to 40°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 Chula Vista, not a forecast for this year.
What to do before the first frost
Zone 10b around Chula Vista 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.
Why 01/06 isn't a guarantee
01/06 is the middle of 30 years of NOAA records, not a promise. Plant by 02/05 and you're betting against frost in roughly 9 years out of 10. 12/13 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Chula Vista compares
At roughly 365 frost-free days, Chula Vista places 306 of 40,283 ZIP codes in this dataset. Within CA, it ranks 99 of 2,555.
Learn more
zone vs. frost date explains why Zone 10b and Chula Vista's frost date answer different questions, and the frost range explains how to read the range around Chula Vista's dates instead of trusting one.