Frost Dates for 85344 — Parker, Arizona

In the 88% of winters that bring a 32°F night, half of springs at Parker, AZ see their last 32°F night by January 12; only one in ten is past it by December 20, and one in ten still has one after February 15. Counting the winters with no freeze at all, the risk of a 32°F night after February 15 is under 9% and after January 12 44%. The 34 days between the even-odds date and the one-in-ten date is wider than at 91% of the 98 Arizona 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 19 in half of years, as early as December 4 one year in ten, and holds off past January 10 one year in ten. A hard freeze of 28°F is less common: it came in 42% of winters. The freeze-free season lasts 338 days in a typical year, longer than at 89% of the 98 Arizona stations; it reaches 365 days one year in ten and falls short of 304 one year in ten. On average 4 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 26 days longer, to about February 7, and return around December 6. A 24°F night is unusual: 7% of winters had one.

July is the warmest month at Parker, AZ, averaging 108°F by day and 81°F at night; December is the coldest at 67°F and 40°F. From March to November the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 21% of years.

Warmth for growing adds up to 8,880 growing degree days a year (base 50°F), more than at 93% of the 102 Arizona stations. 41% of them (3,641) have built up by the end of June, and July adds the most, 1,381. Precipitation totals 4.6 inches a year, most in January (0.9") and least in June (0.0"); May to September bring 24% of it.

The nearest other station, Bouse, AZ, 19 miles southeast of Parker and 505 feet higher, has a last frost 37 days later (February 18), a first frost 21 days earlier (November 28), a season 54 days shorter.

Measurable snow is rare here: only 0 of 23 winters from 1991 to 2020 recorded 0.1 inch or more at Parker, AZ, 3.8 miles away, so there is no typical first-snow date to plan around.

ZIP 85344 is 4 miles from Parker, AZ, which stands at 420 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 85344 in zone 9b, the band where the coldest night of the year averaged 25 to 30°F (-3.9 to -1.1°C) over 1991–2020; a zone describes winter lows, not frost dates.