Frost Dates for 82072 — Laramie, Wyoming

Half of springs at Laramie 2 NW, WY see their last 32°F night by June 7; only one in ten is past it by May 23, and one in ten still has one after June 29. Planting tender crops after June 15 leaves a 30% risk of a frost on them, after June 19 20%, and after June 29 10%. The 22 days between the even-odds date and the one-in-ten date is the widest of the 33 Wyoming stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.

In fall the first 32°F night comes by September 4 in half of years, as early as August 17 one year in ten, and holds off past September 18 one year in ten. A hard freeze of 28°F follows 10 days later, around September 14; in spring the one-in-ten date for 28°F is June 6, 23 days before the 32°F one. The freeze-free season lasts 88 days in a typical year, shorter than at 85% of the 33 Wyoming stations; it reaches 110 days one year in ten and falls short of 61 one year in ten. On average 217 nights a year drop to 32°F or below. Severe cold of 16°F or below comes every winter, usually between October 14 and April 22.

July is the warmest month at Laramie 2 NW, WY, averaging 81°F by day and 47°F at night; December is the coldest at 33°F and 8°F. A freezing night is all but certain in every month from September to May (a 90% chance or more). July is the only month with under a 10% chance of a 32°F night. In spring, June still brings one in 68% of years.

Warmth for growing adds up to 1,225 growing degree days a year (base 50°F), fewer than at 91% of the 33 Wyoming stations. 24% of them (297) have built up by the end of June, and July adds the most, 426. Precipitation totals 11.0 inches a year, most in May (1.8") and least in January (0.3"); May to September bring 60% of it.

The nearest other station, Laramie Regional Airport, WY, 5 miles southwest of Laramie, has a last frost 5 days earlier (June 2), a first frost 11 days later (September 15), a season 14 days longer.

The first measurable snow (0.1 inch or more) in Laramie usually arrives around October 10, and the last of the season around May 18. Those are the middle dates across the winters of 1991–2020 at Laramie 1.3 SE, WY, 3.4 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 20 days after the last snow.

ZIP 82072 is 1 mile from Laramie 2 NW, WY, which stands at 7,140 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 82072 in zone 4a, the band where the coldest night of the year averaged -30 to -25°F (-34.4 to -31.7°C) over 1991–2020; a zone describes winter lows, not frost dates.