Frost Dates for 82834 — Buffalo, Wyoming

Half of springs at Buffalo, WY see their last 32°F night by May 24; only one in ten is past it by May 12, and one in ten still has one after June 9. Planting tender crops after May 31 leaves a 30% risk of a frost on them, after June 3 20%, and after June 9 10%. The 16 days between the even-odds date and the one-in-ten date is wider than at 55% of the 33 Wyoming stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 21 in half of years, as early as September 7 one year in ten, and holds off past October 3 one year in ten. A hard freeze of 28°F follows 9 days later, around September 30; in spring the one-in-ten date for 28°F is May 28, 12 days before the 32°F one. The freeze-free season lasts 118 days in a typical year, shorter than at 70% of the 33 Wyoming stations; it reaches 139 days one year in ten and falls short of 97 one year in ten. On average 184 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 13 days longer, to about June 6, and return around September 11. Severe cold of 16°F or below comes every winter, usually between October 28 and April 6.

July is the warmest month at Buffalo, WY, averaging 83°F by day and 53°F at night; January is the coldest at 36°F and 11°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, June still brings one in 28% of years.

Warmth for growing adds up to 1,787 growing degree days a year (base 50°F), fewer than at 76% of the 33 Wyoming stations. 24% of them (427) have built up by the end of June, and July adds the most, 556. Precipitation totals 13.8 inches a year, most in May (2.8") and least in January (0.4"); May to September bring 62% of it.

The nearest other station, Sheridan Co Airport, WY, 35 miles northwest of Buffalo and 694 feet lower, has a last frost 3 days earlier (May 21), a first frost 2 days later (September 23), a season 5 days longer.

The first measurable snow (0.1 inch or more) in Buffalo usually arrives around October 12, and the last of the season around April 17. Those are the middle dates across the winters of 1991–2020 at Buffalo, WY, 3.9 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 37 days after the last snow.

ZIP 82834 is 4 miles from Buffalo, WY, which stands at 4,639 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 82834 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°C) over 1991–2020; a zone describes winter lows, not frost dates.