Barstow, CA 92365 Frost Dates
92365, near Barstow, CA: the frost window
Typically, the last spring freeze lands around 02/19, roughly 175 days out. Fall's first freeze usually shows up around 11/26, roughly 279 days after the last spring frost.
Zone 9a (20 to 25°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 Barstow, not a forecast for this year.
Stretching the season past the first frost
Barstow's growing season runs out in roughly 13 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 02/19 isn't a guarantee
02/19 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/23 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 03/11 and only about 1 year in 10 sees frost after that.
Barstow against the rest of the dataset
About 279 days separate Barstow's last and first frost, putting it 4,869 of 40,283 ZIP codes nationally. Within CA, it ranks 1,789 of 2,555.
Learn more
Two guides worth reading on 92365: local microclimates, on what one yard in Barstow can differ from the 92365 normal, and zone vs. frost date, on why Zone 9a and Barstow's frost date answer different questions.