Chula Vista, CA 91914 Frost Dates
91914, near Chula Vista, CA: the frost window
Around 01/06 is the usual last spring frost, about 131 days away. Fall's first freeze usually shows up around 12/31, roughly 365 days after the last spring frost.
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.
Stretching the season past the first frost
Chula Vista's growing season runs out in roughly 18 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 01/06 isn't a guarantee
01/06 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/05 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/13 and only about 1 year in 10 sees frost after that.
Chula Vista against the rest of the dataset
Chula Vista's growing season runs about 365 days, ranking 307 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 100 of 2,555.
Learn more
Two guides worth reading on 91914: local microclimates, on what one yard in Chula Vista can differ from the 91914 normal, and zone vs. frost date, on why Zone 10b and Chula Vista's frost date answer different questions.