Frost Dates for 98942 — Selah, Washington

Half of springs at Selah 2 NE, WA see their last 32°F night by May 5; only one in ten is past it by April 24, and one in ten still has one after May 23. Planting tender crops after May 13 leaves a 30% risk of a frost on them, after May 17 20%, and after May 23 10%. The 18 days between the even-odds date and the one-in-ten date is narrower than at 56% of the 113 Washington stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 4 in half of years, as early as September 23 one year in ten, and holds off past October 18 one year in ten. A hard freeze of 28°F follows 13 days later, around October 17; in spring the one-in-ten date for 28°F is May 7, 16 days before the 32°F one. The freeze-free season lasts 149 days in a typical year, shorter than at 87% of the 113 Washington stations; it reaches 168 days one year in ten and falls short of 128 one year in ten. On average 168 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 19 days longer, to about May 24, and return around September 24. Severe cold of 16°F or below comes every winter, usually between November 24 and February 20.

July is the warmest month at Selah 2 NE, WA, averaging 88°F by day and 54°F at night; December is the coldest at 37°F and 21°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 67% of years.

Warmth for growing adds up to 2,371 growing degree days a year (base 50°F), more than at 68% of the 113 Washington stations. 30% of them (709) have built up by the end of June, and July adds the most, 648. Precipitation totals 8.6 inches a year, most in December (1.4") and least in July (0.2"); May to September bring 28% of it.

The nearest other station, Yakima #2, WA, 10 miles south of Selah, has a last frost 27 days earlier (April 8), a first frost 19 days later (October 23), a season 47 days longer.

The first measurable snow (0.1 inch or more) in Selah usually arrives around November 25, and the last of the season around March 1. Those are the middle dates across the winters of 1991–2020 at Yakima Air Terminal, WA, 11 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 65 days after the last snow.

ZIP 98942 is 5 miles from Selah 2 NE, WA, which stands at 1,120 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 98901 (Yakima). The 2023 USDA Plant Hardiness Zone Map lists ZIP 98942 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.