Frost Dates for 92311 — Barstow, California

Half of springs at Barstow, CA see their last 32°F night by February 22; only one in ten is past it by January 29, and one in ten still has one after March 24. Planting tender crops after March 3 leaves a 30% risk of a frost on them, after March 10 20%, and after March 24 10%. The 30 days between the even-odds date and the one-in-ten date is narrower than at 48% of the 220 California stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.

In fall the first 32°F night comes by November 23 in half of years, as early as November 9 one year in ten, and holds off past December 8 one year in ten. A hard freeze of 28°F follows 13 days later, around December 6; in spring the one-in-ten date for 28°F is February 25, 27 days before the 32°F one. The freeze-free season lasts 271 days in a typical year, shorter than at 55% of the 219 California stations; it reaches 304 days one year in ten and falls short of 239 one year in ten. On average 32 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 23 days longer, to about March 17, and return around November 12. Nights of 24°F, cold enough to damage hardier plants, come in 81% of winters and 16°F in 4%.

July is the warmest month at Barstow, CA, averaging 102°F by day and 72°F at night; December is the coldest at 57°F and 35°F. A freezing night is all but certain in every month from December to January (a 90% chance or more). From April to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 80% of years and March still brings one in 32% of years.

Warmth for growing adds up to 6,141 growing degree days a year (base 50°F), more than at 94% of the 283 California stations. 38% of them (2,322) have built up by the end of June, and July adds the most, 1,145. Precipitation totals 5.2 inches a year, most in February (1.0") and least in June (0.0"); May to September bring 17% of it.

The nearest other station, Barstow Daggett Airport, CA, 14 miles east of Barstow and 303 feet lower, has a last frost 3 days earlier (February 19), a first frost 3 days later (November 26), a season 8 days longer.

Measurable snow is rare here: only 3 of 30 winters from 1991 to 2020 recorded 0.1 inch or more at Barstow, CA, 0.8 miles away, so there is no typical first-snow date to plan around.

ZIP 92311 is under a mile from Barstow, CA, which stands at 2,220 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 92311 in zone 9a, the band where the coldest night of the year averaged 20 to 25°F (-6.7 to -3.9°C) over 1991–2020; a zone describes winter lows, not frost dates.