Frost Dates for 84044 — Magna, Utah

Half of springs at Garfield, UT see their last 32°F night by April 3; only one in ten is past it by March 11, and one in ten still has one after April 19. Planting tender crops after April 11 leaves a 30% risk of a frost on them, after April 14 20%, and after April 19 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 83% of the 66 Utah stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 4 in half of years, as early as October 18 one year in ten, and holds off past November 17 one year in ten. A hard freeze of 28°F follows 9 days later, around November 13; in spring the one-in-ten date for 28°F is April 6, 13 days before the 32°F one. The freeze-free season lasts 213 days in a typical year, longer than at 95% of the 66 Utah stations; it reaches 238 days one year in ten and falls short of 190 one year in ten. On average 97 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 April 19, and return around October 23. Severe cold of 16°F or below comes in 95% of winters, usually between December 15 and January 31.

July is the warmest month at Garfield, UT, averaging 91°F by day and 71°F at night; January is the coldest at 36°F and 25°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 57% of years.

Warmth for growing adds up to 3,826 growing degree days a year (base 50°F), more than at 89% of the 66 Utah stations. 31% of them (1,201) have built up by the end of June, and July adds the most, 968. Precipitation totals 17.6 inches a year, most in May (2.4") and least in July (0.7"); May to September bring 34% of it.

The nearest other station, Salt Lake City International Airport, UT, 8 miles northeast of Magna, has a last frost 5 days later (April 8), a first frost 4 days earlier (October 31), a season 9 days shorter.

The first measurable snow (0.1 inch or more) in Magna usually arrives around November 24, and the last of the season around March 5. Those are the middle dates across the winters of 1991–2020 at Garfield, UT, 6.2 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 29 days after the last snow.

ZIP 84044 is 6 miles from Garfield, UT, which stands at 4,298 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 84044 in zone 7b, the band where the coldest night of the year averaged 5 to 10°F (-15.0 to -12.2°C) over 1991–2020; a zone describes winter lows, not frost dates.