Frost Dates for 97918 — Vale, Oregon

Half of springs at Vale, OR see their last 32°F night by May 8; only one in ten is past it by April 23, and one in ten still has one after June 7. Planting tender crops after May 16 leaves a 30% risk of a frost on them, after May 25 20%, and after June 7 10%. The 30 days between the even-odds date and the one-in-ten date is wider than at 87% 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 29 in half of years, as early as September 11 one year in ten, and holds off past October 11 one year in ten. A hard freeze of 28°F follows 10 days later, around October 9; in spring the one-in-ten date for 28°F is May 14, 24 days before the 32°F one. The freeze-free season lasts 140 days in a typical year, shorter than at 83% of the 103 Oregon stations; it reaches 162 days one year in ten and falls short of 109 one year in ten. On average 147 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 23 days longer, to about May 31, and return around September 17. Severe cold of 16°F or below comes every winter, usually between November 14 and February 26.

July is the warmest month at Vale, OR, averaging 93°F by day and 57°F at night; December is the coldest at 37°F and 19°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 64% of years and June still brings one in 15% of years.

Warmth for growing adds up to 2,730 growing degree days a year (base 50°F), more than at 80% of the 103 Oregon stations. 30% of them (826) have built up by the end of June, and July adds the most, 770. Precipitation totals 10.1 inches a year, most in May (1.3") and least in August (0.2"); May to September bring 31% of it.

The nearest other station, Ontario Ksrv, OR, 18 miles east of Vale, has a last frost 16 days earlier (April 22), a first frost 10 days later (October 9), a season 28 days longer.

The first measurable snow (0.1 inch or more) in Vale usually arrives around December 2, and the last of the season around February 12. Those are the middle dates across the winters of 1991–2020 at Malheur Branch Exp Stn, OR, 15.7 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 85 days after the last snow.

ZIP 97918 is 6 miles from Vale, OR, which stands at 2,240 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 97918 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°C) over 1991–2020; a zone describes winter lows, not frost dates.