Chula Vista, CA 91917 Frost Dates
Frost dates for Chula Vista, CA, ZIP 91917
The last spring frost here typically falls around 04/30, about 245 days from today. The first fall frost typically arrives around 10/26, about 174 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 Chula Vista, not a forecast for this year.
What to do before the first frost
Zone 10a around Chula Vista has about 8 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.
The actual range around Chula Vista's last frost
04/30 is the middle of 30 years of NOAA records, not a promise. Plant by 04/09 and you're betting against frost in roughly 9 years out of 10. 06/01 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Chula Vista compares
About 174 days separate Chula Vista's last and first frost, putting it 27,308 of 40,283 ZIP codes nationally. Within CA, it ranks 2,359 of 2,555.
Learn more
the frost range explains how to read the range around Chula Vista's dates instead of trusting one, and local microclimates explains what one yard in Chula Vista can differ from the 91917 normal.