Frost Dates for 97707 — Bend, Oregon

Half of springs at Wickiup Dam, OR see their last 32°F night by June 7; only one in ten is past it by May 16, and one in ten still has one after July 2. Planting tender crops after June 16 leaves a 30% risk of a frost on them, after June 21 20%, and after July 2 10%. The 25 days between the even-odds date and the one-in-ten date is wider than at 68% of the 103 Oregon 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 18 in half of years, as early as September 3 one year in ten, and holds off past October 3 one year in ten. A hard freeze of 28°F follows 15 days later, around October 3; in spring the one-in-ten date for 28°F is June 13, 19 days before the 32°F one. The freeze-free season lasts 100 days in a typical year, shorter than at 95% of the 103 Oregon stations; it reaches 128 days one year in ten and falls short of 69 one year in ten. On average 201 nights a year drop to 32°F or below. Severe cold of 16°F or below comes every winter, usually between November 18 and March 9.

July is the warmest month at Wickiup Dam, OR, averaging 83°F by day and 47°F at night; December is the coldest at 38°F and 21°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). August is the only month with under a 10% chance of a 32°F night. In spring, June still brings one in 58% of years and July still brings one in 11% of years.

Warmth for growing adds up to 1,514 growing degree days a year (base 50°F), fewer than at 87% of the 103 Oregon stations. 22% of them (337) have built up by the end of June, and July adds the most, 463. Precipitation totals 19.6 inches a year, most in December (3.6") and least in July (0.5"); May to September bring 20% of it.

The nearest other station, Bend, OR, 17 miles northeast of Bend and 698 feet lower, has a last frost 1 day earlier (June 6), a first frost 2 days later (September 20), a season 5 days longer.

The first measurable snow (0.1 inch or more) in Bend usually arrives around November 3, and the last of the season around April 21. Those are the middle dates across the winters of 1991–2020 at Sunriver, OR, 4.1 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 47 days after the last snow.

ZIP 97707 is 16 miles from Wickiup Dam, OR, which stands at 4,358 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 97739 (La Pine). The 2023 USDA Plant Hardiness Zone Map lists ZIP 97707 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.