Frost Dates for 84653 — Salem, Utah

Half of springs at Spanish Fk Pwr House, UT see their last 32°F night by April 25; only one in ten is past it by April 10, and one in ten still has one after May 13. Planting tender crops after May 2 leaves a 30% risk of a frost on them, after May 5 20%, and after May 13 10%. The 18 days between the even-odds date and the one-in-ten date is narrower than at 47% of the 66 Utah stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 18 in half of years, as early as October 4 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 30; in spring the one-in-ten date for 28°F is April 25, 18 days before the 32°F one. The freeze-free season lasts 174 days in a typical year, longer than at 67% of the 66 Utah stations; it reaches 195 days one year in ten and falls short of 151 one year in ten. On average 118 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 16 days longer, to about May 11, and return around October 6. Severe cold of 16°F or below comes every winter, usually between November 27 and February 23.

July is the warmest month at Spanish Fk Pwr House, UT, averaging 93°F by day and 61°F at night; January is the coldest at 38°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 September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 34% of years.

Warmth for growing adds up to 3,347 growing degree days a year (base 50°F), more than at 76% of the 66 Utah stations. 31% of them (1,052) have built up by the end of June, and July adds the most, 840. Precipitation totals 20.3 inches a year, most in April (2.5") and least in July (0.6"); May to September bring 29% of it.

The nearest other station, Santaquin Chlorinator, UT, 9 miles southwest of Salem and 440 feet higher, has a last frost 9 days later (May 4), a first frost 7 days earlier (October 11), a season 17 days shorter.

The first measurable snow (0.1 inch or more) in Salem usually arrives around November 9, and the last of the season around April 9. Those are the middle dates across the winters of 1991–2020 at Spanish Fk Pwr House, UT, 4 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 16 days after the last snow.

ZIP 84653 is 4 miles from Spanish Fk Pwr House, UT, which stands at 4,720 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 84660 (Spanish Fork). The 2023 USDA Plant Hardiness Zone Map lists ZIP 84653 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.