Frost Dates for 85936 — Saint Johns, Arizona

Half of springs at Saint Johns, AZ see their last 32°F night by May 2; only one in ten is past it by April 18, and one in ten still has one after May 17. Planting tender crops after May 7 leaves a 30% risk of a frost on them, after May 12 20%, and after May 17 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 91% of the 98 Arizona stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 14 in half of years, as early as October 3 one year in ten, and holds off past October 27 one year in ten. A hard freeze of 28°F follows 9 days later, around October 23; in spring the one-in-ten date for 28°F is May 5, 12 days before the 32°F one. The freeze-free season lasts 164 days in a typical year, shorter than at 81% of the 98 Arizona stations; it reaches 182 days one year in ten and falls short of 147 one year in ten. On average 144 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 12 days longer, to about May 14, and return around October 6. Severe cold of 16°F or below comes every winter, usually between November 22 and March 2.

July is the warmest month at Saint Johns, AZ, averaging 91°F by day and 60°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 September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 56% of years.

Warmth for growing adds up to 3,399 growing degree days a year (base 50°F), fewer than at 79% of the 102 Arizona stations. 35% of them (1,183) have built up by the end of June, and July adds the most, 784. Precipitation totals 9.6 inches a year, most in August (2.0") and least in June (0.2"); May to September bring 58% of it.

The nearest other station, Springerville, AZ, 30 miles south of Saint Johns and 1,208 feet higher, has a last frost 30 days later (June 1), a first frost 18 days earlier (September 26), a season 50 days shorter.

The first measurable snow (0.1 inch or more) in Saint Johns usually arrives around December 18, and the last of the season around February 14. Those are the middle dates across the winters of 1991–2020 at Saint Johns, AZ, 2.9 miles away: half of years saw snow earlier, half later. Snow fell in 89% of those winters. The last 32°F night of spring typically comes 77 days after the last snow.

ZIP 85936 is 3 miles from Saint Johns, AZ, which stands at 5,790 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 85936 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.