Frost Dates for 85131 — Eloy, Arizona

Half of springs at Arizona City, AZ see their last 32°F night by February 28; only one in ten is past it by February 3, and one in ten still has one after March 14. Planting tender crops after March 5 leaves a 30% risk of a frost on them, after March 8 20%, and after March 14 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 95% of the 98 Arizona stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 21 in half of years, as early as November 5 one year in ten, and holds off past December 6 one year in ten. A hard freeze of 28°F follows 13 days later, around December 4; in spring the one-in-ten date for 28°F is March 1, 13 days before the 32°F one. The freeze-free season lasts 266 days in a typical year, longer than at 59% of the 98 Arizona stations; it reaches 294 days one year in ten and falls short of 243 one year in ten. On average 33 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 17 days longer, to about March 17, and return around November 12. Nights of 24°F, cold enough to damage hardier plants, come in 89% of winters and 16°F in 4%.

July is the warmest month at Arizona City, AZ, averaging 104°F by day and 76°F at night; December is the coldest at 64°F and 34°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 89% of years and March still brings one in 45% of years.

Warmth for growing adds up to 7,171 growing degree days a year (base 50°F), more than at 61% of the 102 Arizona stations. 39% of them (2,820) have built up by the end of June, and July adds the most, 1,224. Precipitation totals 7.9 inches a year, most in July (1.2") and least in April (0.1"); May to September bring 46% of it.

The nearest other station, Picacho 8 SE, AZ, 11 miles east of Eloy and 456 feet higher, has a last frost 22 days earlier (February 6), a first frost 18 days later (December 9), a season 42 days longer.

Measurable snow is rare here: only 0 of 15 winters from 1991 to 2020 recorded 0.1 inch or more at Eloy 4 NE, AZ, 10 miles away, so there is no typical first-snow date to plan around.

ZIP 85131 is 8 miles from Arizona City, AZ, which stands at 1,525 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 85131 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.