Frost Dates for 98612 — Cathlamet, Washington

Half of springs at Clatskanie, OR see their last 32°F night by April 24; only one in ten is past it by March 31, and one in ten still has one after May 9. Planting tender crops after May 1 leaves a 30% risk of a frost on them, after May 4 20%, and after May 9 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 81% of the 113 Washington stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 24 in half of years, as early as October 5 one year in ten, and holds off past November 12 one year in ten. A hard freeze of 28°F follows 16 days later, around November 9; in spring the one-in-ten date for 28°F is April 20, 19 days before the 32°F one. The freeze-free season lasts 184 days in a typical year, shorter than at 56% of the 113 Washington stations; it reaches 210 days one year in ten and falls short of 159 one year in ten. On average 70 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 17 days longer, to about May 11, and return around October 7. Nights of 24°F, cold enough to damage hardier plants, come in 98% of winters and 16°F in 33%.

August is the warmest month at Clatskanie, OR, averaging 76°F by day and 52°F at night; December is the coldest at 46°F and 33°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 85% of years and May still brings one in 30% of years.

Warmth for growing adds up to 1,724 growing degree days a year (base 50°F), fewer than at 75% of the 113 Washington stations. 28% of them (478) have built up by the end of June, and August adds the most, 434. Precipitation totals 54.7 inches a year, most in December (9.4") and least in July (0.6"); May to September bring 14% of it.

The nearest other station, Longview, WA, 21 miles east of Cathlamet, has a last frost 16 days earlier (April 8), a first frost 12 days later (November 5), a season 26 days longer.

Measurable snow is rare here: only 8 of 18 winters from 1991 to 2020 recorded 0.1 inch or more at Cathlamet 6NE, WA, 1.4 miles away, so there is no typical first-snow date to plan around.

ZIP 98612 is 10 miles from Clatskanie, OR, which stands at 22 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 97016 (Clatskanie). The 2023 USDA Plant Hardiness Zone Map lists ZIP 98612 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.