Frost Dates for 85602 — Benson, Arizona

Half of springs at Benson 6SE, AZ see their last 32°F night by April 12; only one in ten is past it by March 26, and one in ten still has one after April 29. Planting tender crops after April 19 leaves a 30% risk of a frost on them, after April 23 20%, and after April 29 10%. The 17 days between the even-odds date and the one-in-ten date is narrower than at 80% of the 98 Arizona stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 1 in half of years, as early as October 18 one year in ten, and holds off past November 15 one year in ten. A hard freeze of 28°F follows 10 days later, around November 11; in spring the one-in-ten date for 28°F is April 13, 16 days before the 32°F one. The freeze-free season lasts 202 days in a typical year, shorter than at 66% of the 98 Arizona stations; it reaches 224 days one year in ten and falls short of 181 one year in ten. On average 93 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 14 days longer, to about April 26, and return around October 24. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 85%.

July is the warmest month at Benson 6SE, AZ, averaging 98°F by day and 66°F at night; December is the coldest at 64°F and 27°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 80% of years.

Warmth for growing adds up to 5,335 growing degree days a year (base 50°F), fewer than at 55% of the 102 Arizona stations. 38% of them (2,042) have built up by the end of June, and July adds the most, 983. Precipitation totals 11.9 inches a year, most in August (2.8") and least in April (0.2"); May to September bring 64% of it.

The nearest other station, Saguaro Np, AZ, 27 miles northwest of Benson and 610 feet lower, has a last frost 76 days earlier (January 26), a first frost 45 days later (December 16), a season 124 days longer.

Measurable snow is rare here: only 4 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Benson 6SE, AZ, 10 miles away, so there is no typical first-snow date to plan around.

ZIP 85602 is 10 miles from Benson 6SE, AZ, which stands at 3,690 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 85602 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.