Frost Dates for 86044 — Tonalea, Arizona

Half of springs at Betatakin, AZ see their last 32°F night by May 7; only one in ten is past it by April 23, and one in ten still has one after May 26. Planting tender crops after May 14 leaves a 30% risk of a frost on them, after May 20 20%, and after May 26 10%. The 19 days between the even-odds date and the one-in-ten date is narrower than at 61% of the 98 Arizona stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 15 in half of years, as early as September 30 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 12 days later, around October 27; in spring the one-in-ten date for 28°F is May 12, 14 days before the 32°F one. The freeze-free season lasts 159 days in a typical year, shorter than at 85% of the 98 Arizona stations; it reaches 183 days one year in ten and falls short of 133 one year in ten. On average 139 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 13 days longer, to about May 20, and return around October 6. Severe cold of 16°F or below comes every winter, usually between November 27 and February 28.

July is the warmest month at Betatakin, AZ, averaging 86°F by day and 60°F at night; January is the coldest at 40°F and 22°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 72% of years.

Warmth for growing adds up to 2,825 growing degree days a year (base 50°F), fewer than at 89% of the 102 Arizona stations. 32% of them (896) have built up by the end of June, and July adds the most, 710. Precipitation totals 11.2 inches a year, most in August (1.5") and least in June (0.2"); May to September bring 42% of it.

The nearest other station, Tuba City, AZ, 33 miles southwest of Tonalea and 2,298 feet lower, has a last frost 21 days earlier (April 16), a first frost 13 days later (October 28), a season 34 days longer.

The first measurable snow (0.1 inch or more) in Tonalea usually arrives around November 22, and the last of the season around March 29. Those are the middle dates across the winters of 1991–2020 at Betatakin, AZ, 21.6 miles away: half of years saw snow earlier, half later. Snow fell in 97% of those winters. The last 32°F night of spring typically comes 39 days after the last snow.

ZIP 86044 is 22 miles from Betatakin, AZ, which stands at 7,286 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 86033 (Kayenta). The 2023 USDA Plant Hardiness Zone Map lists ZIP 86044 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°C) over 1991–2020; a zone describes winter lows, not frost dates.