Frost Dates for 97720 — Burns, Oregon

Half of springs at Burns Municipal Airport, OR see their last 32°F night by June 11; only one in ten is past it by May 21, and one in ten still has one after June 28. Planting tender crops after June 19 leaves a 30% risk of a frost on them, after June 23 20%, and after June 28 10%. The 17 days between the even-odds date and the one-in-ten date is narrower than at 83% of the 103 Oregon stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 6 in half of years, as early as August 21 one year in ten, and holds off past September 20 one year in ten. A hard freeze of 28°F follows 13 days later, around September 19; in spring the one-in-ten date for 28°F is June 14, 14 days before the 32°F one. The freeze-free season lasts 85 days in a typical year, shorter than at 99% of the 103 Oregon stations; it reaches 111 days one year in ten and falls short of 59 one year in ten. On average 207 nights a year drop to 32°F or below. Severe cold of 16°F or below comes every winter, usually between October 26 and March 15.

July is the warmest month at Burns Municipal Airport, OR, averaging 89°F by day and 49°F at night; December is the coldest at 36°F and 16°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 76% of years.

Warmth for growing adds up to 1,855 growing degree days a year (base 50°F), fewer than at 70% of the 103 Oregon stations. 25% of them (468) have built up by the end of June, and July adds the most, 578. Precipitation totals 10.5 inches a year, most in December (1.5") and least in July (0.3"); May to September bring 29% of it.

The nearest other station, O O Rch, OR, 28 miles southwest of Burns, has the same 50% last-frost date, the same first-frost date, a season 3 days longer.

The first measurable snow (0.1 inch or more) in Burns usually arrives around November 21, and the last of the season around March 5. Those are the middle dates across the winters of 1991–2020 at Drewsey, OR, 32.6 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 98 days after the last snow.

ZIP 97720 is under a mile from Burns Municipal Airport, OR, which stands at 4,140 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 97720 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°C) over 1991–2020; a zone describes winter lows, not frost dates.