Frost Dates for 86321 — Bagdad, Arizona

Half of springs at Bagdad, AZ see their last 32°F night by April 7; only one in ten is past it by March 14, and one in ten still has one after May 3. Planting tender crops after April 18 leaves a 30% risk of a frost on them, after April 24 20%, and after May 3 10%. The 26 days between the even-odds date and the one-in-ten date is wider than at 67% 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 November 12 in half of years, as early as October 26 one year in ten, and holds off past November 25 one year in ten. A hard freeze of 28°F follows 10 days later, around November 22; in spring the one-in-ten date for 28°F is April 8, 25 days before the 32°F one. The freeze-free season lasts 217 days in a typical year, shorter than at 60% of the 98 Arizona stations; it reaches 244 days one year in ten and falls short of 188 one year in ten. On average 60 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 19 days longer, to about April 26, and return around November 1. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 29%.

July is the warmest month at Bagdad, AZ, averaging 95°F by day and 66°F at night; December is the coldest at 56°F and 30°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 62% of years and May still brings one in 13% of years.

Warmth for growing adds up to 4,596 growing degree days a year (base 50°F), fewer than at 68% of the 102 Arizona stations. 34% of them (1,562) have built up by the end of June, and July adds the most, 936. Precipitation totals 15.8 inches a year, most in February (2.3") and least in June (0.2"); May to September bring 35% of it.

The nearest other station, Prescott, AZ, 39 miles east of Bagdad and 1,270 feet higher, has a last frost 23 days later (April 30), a first frost 23 days earlier (October 20), a season 45 days shorter.

The first measurable snow (0.1 inch or more) in Bagdad usually arrives around December 28, and the last of the season around February 16. Those are the middle dates across the winters of 1991–2020 at Bagdad, AZ, 5 miles away: half of years saw snow earlier, half later. Snow fell in 67% of those winters. The last 32°F night of spring typically comes 50 days after the last snow.

ZIP 86321 is 5 miles from Bagdad, AZ, which stands at 3,935 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 86321 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.