Frost Dates for 92274 — Thermal, California

In the 70% of winters that bring a 32°F night, half of springs at Mecca Fire Stn, CA see their last 32°F night by January 6; only one in ten is past it by December 13, and one in ten still has one after February 4. Counting the winters with no freeze at all, the risk of a 32°F night after February 4 is under 7% and after January 6 35%. The 29 days between the even-odds date and the one-in-ten date is narrower than at 52% 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 December 22 in half of years, as early as December 4 one year in ten, and holds off past January 14 one year in ten. A hard freeze of 28°F is less common: it came in 21% of winters. The freeze-free season lasts 352 days in a typical year, longer than at 95% of the 219 California stations; it reaches 365 days one year in ten and falls short of 321 one year in ten. On average 8 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 22 days longer, to about January 28, and return around December 10. A 24°F night is unusual: 3% of winters had one.

July is the warmest month at Mecca Fire Stn, CA, averaging 107°F by day and 80°F at night; December is the coldest at 69°F and 42°F. From February to November the chance of a 32°F night stays under 10% each month.

Warmth for growing adds up to 9,062 growing degree days a year (base 50°F), more than at 98% of the 283 California stations. 42% of them (3,819) have built up by the end of June, and July adds the most, 1,342. Precipitation totals 3.1 inches a year, most in January (0.6") and least in May (0.0"); May to September bring 19% of it.

The nearest other station, Indio Fire Stn, CA, 19 miles northwest of Thermal and 162 feet higher, has a 32°F night in 30% of winters against 70% here, and a coolest-month low 3°F warmer (45°F).

Measurable snow is rare here: only 0 of 18 winters from 1991 to 2020 recorded 0.1 inch or more at Mecca Fire Stn, CA, 7.1 miles away, so there is no typical first-snow date to plan around.

ZIP 92274 is 7 miles from Mecca Fire Stn, CA, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 92274 in zone 10a, the band where the coldest night of the year averaged 30 to 35°F (-1.1 to 1.7°C) over 1991–2020; a zone describes winter lows, not frost dates.