Frost Dates for 98331 — Forks, Washington

Half of springs at Forks 1 E, WA see their last 32°F night by April 26; only one in ten is past it by April 5, and one in ten still has one after May 10. Planting tender crops after May 1 leaves a 30% risk of a frost on them, after May 5 20%, and after May 10 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 25 in half of years, as early as October 6 one year in ten, and holds off past November 15 one year in ten. A hard freeze of 28°F follows 21 days later, around November 15; in spring the one-in-ten date for 28°F is April 21, 19 days before the 32°F one. The freeze-free season lasts 182 days in a typical year, shorter than at 57% of the 113 Washington stations; it reaches 210 days one year in ten and falls short of 158 one year in ten. On average 60 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 18 days longer, to about May 14, and return around October 5. Nights of 24°F, cold enough to damage hardier plants, come in 97% of winters and 16°F in 15%.

August is the warmest month at Forks 1 E, WA, averaging 74°F by day and 51°F at night; December is the coldest at 46°F and 34°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 89% of years and May still brings one in 33% of years.

Warmth for growing adds up to 1,507 growing degree days a year (base 50°F), fewer than at 88% of the 113 Washington stations. 27% of them (410) have built up by the end of June, and August adds the most, 380. Precipitation totals 120.1 inches a year, most in January (19.1") and least in July (2.1"); May to September bring 15% of it.

The nearest other station, Elwha Rs, WA, 38 miles east of Forks, has a last frost 17 days earlier (April 9), a first frost 9 days later (November 3), a season 27 days longer.

The first measurable snow (0.1 inch or more) in Forks usually arrives around December 21, and the last of the season around March 1. Those are the middle dates across the winters of 1991–2020 at Forks 1 E, WA, 8.1 miles away: half of years saw snow earlier, half later. Snow fell in 85% of those winters. The last 32°F night of spring typically comes 56 days after the last snow.

ZIP 98331 is 8 miles from Forks 1 E, WA, which stands at 350 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 98331 in zone 8b, the band where the coldest night of the year averaged 15 to 20°F (-9.4 to -6.7°C) over 1991–2020; a zone describes winter lows, not frost dates.