Barstow, CA 92398 Frost Dates
92398, 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.
The USDA Plant Hardiness Zone Map puts Barstow in Zone 9a (20 to 25°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
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.
The actual range around Barstow's last frost
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
At roughly 279 frost-free days, Barstow places 4,870 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,790 of 2,555.
Learn more
Two guides worth reading on 92398: local microclimates, on what one yard in Barstow can differ from the 92398 normal, and zone vs. frost date, on why Zone 9a and Barstow's frost date answer different questions.