Frost Dates for 92301 — Adelanto, California

Half of springs at El Mirage, CA see their last 32°F night by March 21; only one in ten is past it by February 25, and one in ten still has one after April 22. Planting tender crops after April 6 leaves a 30% risk of a frost on them, after April 13 20%, and after April 22 10%. The 32 days between the even-odds date and the one-in-ten date is wider than at 55% 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 12 in half of years, as early as October 28 one year in ten, and holds off past December 1 one year in ten. A hard freeze of 28°F follows 15 days later, around November 27; in spring the one-in-ten date for 28°F is April 2, 20 days before the 32°F one. The freeze-free season lasts 235 days in a typical year, shorter than at 72% of the 219 California stations; it reaches 269 days one year in ten and falls short of 202 one year in ten. On average 71 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 25 days longer, to about April 15, and return around November 1. Nights of 24°F, cold enough to damage hardier plants, come in 99% of winters and 16°F in 26%.

July is the warmest month at El Mirage, CA, averaging 98°F by day and 64°F at night; December is the coldest at 56°F and 31°F. A freezing night is all but certain in every month from December to February (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, March still brings one in 74% of years and April still brings one in 35% of years.

Warmth for growing adds up to 4,752 growing degree days a year (base 50°F), more than at 57% of the 283 California stations. 35% of them (1,652) have built up by the end of June, and July adds the most, 956. Precipitation totals 5.6 inches a year, most in February (1.1") and least in June (0.1"); May to September bring 18% of it.

The nearest other station, Victorville, CA, 15 miles southeast of Adelanto, has a last frost 3 days earlier (March 18), a first frost 1 day earlier (November 11), a season 2 days shorter.

Measurable snow is rare here: only 2 of 18 winters from 1991 to 2020 recorded 0.1 inch or more at Victorville, CA, 14.5 miles away, so there is no typical first-snow date to plan around.

ZIP 92301 is 8 miles from El Mirage, CA, which stands at 2,950 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 92301 in zone 8b, the band where the coldest night of the year averaged 15 to 20°F (-9.4 to -6.7°C) over 1991–2020; a zone describes winter lows, not frost dates.