Frost Dates for 98857 — Warden, Washington

Half of springs at Moses Lake Grant Co Airport, WA see their last 32°F night by April 27; only one in ten is past it by April 10, and one in ten still has one after May 11. Planting tender crops after May 2 leaves a 30% risk of a frost on them, after May 6 20%, and after May 11 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 88% of the 113 Washington stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 8 in half of years, as early as September 29 one year in ten, and holds off past October 23 one year in ten. A hard freeze of 28°F follows 12 days later, around October 20; in spring the one-in-ten date for 28°F is April 30, 11 days before the 32°F one. The freeze-free season lasts 165 days in a typical year, shorter than at 75% of the 113 Washington stations; it reaches 186 days one year in ten and falls short of 146 one year in ten. On average 129 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 12 days longer, to about May 9, and return around September 29. Severe cold of 16°F or below comes in 99% of winters, usually between November 26 and February 7.

July is the warmest month at Moses Lake Grant Co Airport, WA, averaging 90°F by day and 57°F at night; December is the coldest at 36°F and 24°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 35% of years.

Warmth for growing adds up to 2,772 growing degree days a year (base 50°F), more than at 84% of the 113 Washington stations. 32% of them (878) have built up by the end of June, and July adds the most, 727. Precipitation totals 8.0 inches a year, most in December (1.1") and least in August (0.2"); May to September bring 27% of it.

The nearest other station, Connell 1 W, WA, 23 miles south of Warden and 176 feet lower, has a last frost 3 days later (April 30), a first frost 4 days later (October 12).

The first measurable snow (0.1 inch or more) in Warden usually arrives around December 4, and the last of the season around February 28. Those are the middle dates across the winters of 1991–2020 at Lind 3 NE, WA, 23.7 miles away: half of years saw snow earlier, half later. Snow fell in 97% of those winters. The last 32°F night of spring typically comes 58 days after the last snow.

ZIP 98857 is 20 miles from Moses Lake Grant Co Airport, WA, which stands at 1,196 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 98837 (Moses Lake). The 2023 USDA Plant Hardiness Zone Map lists ZIP 98857 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.