Frost Dates for 85937 — Snowflake, Arizona

Half of springs at Snowflake, AZ see their last 32°F night by May 11; only one in ten is past it by April 27, and one in ten still has one after May 31. Planting tender crops after May 17 leaves a 30% risk of a frost on them, after May 22 20%, and after May 31 10%. The 20 days between the even-odds date and the one-in-ten date is narrower than at 52% of the 98 Arizona stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 10 in half of years, as early as September 28 one year in ten, and holds off past October 22 one year in ten. A hard freeze of 28°F follows 10 days later, around October 20; in spring the one-in-ten date for 28°F is May 15, 16 days before the 32°F one. The freeze-free season lasts 149 days in a typical year, shorter than at 88% of the 98 Arizona stations; it reaches 169 days one year in ten and falls short of 126 one year in ten. On average 149 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 15 days longer, to about May 26, and return around October 2. Severe cold of 16°F or below comes every winter, usually between November 20 and March 3.

July is the warmest month at Snowflake, AZ, averaging 90°F by day and 58°F at night; December is the coldest at 49°F and 20°F. A freezing night is all but certain in every month from October 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 80% of years.

Warmth for growing adds up to 3,034 growing degree days a year (base 50°F), fewer than at 84% of the 102 Arizona stations. 32% of them (960) have built up by the end of June, and July adds the most, 738. Precipitation totals 11.0 inches a year, most in July (2.2") and least in June (0.3"); May to September bring 55% of it.

The nearest other station, Show Low Airport, AZ, 21 miles south of Snowflake and 769 feet higher, has a last frost 6 days earlier (May 5), a first frost 5 days later (October 15), a season 13 days longer.

The first measurable snow (0.1 inch or more) in Snowflake usually arrives around December 3, and the last of the season around March 4. Those are the middle dates across the winters of 1991–2020 at Snowflake, AZ, 4.5 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 68 days after the last snow.

ZIP 85937 is 5 miles from Snowflake, AZ, which stands at 5,642 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 85937 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.