Frost Dates for 97146 — Warrenton, Oregon

Half of springs at Fort Clatsop Natl Mem, OR see their last 32°F night by March 30; only one in ten is past it by February 26, and one in ten still has one after April 28. Planting tender crops after April 11 leaves a 30% risk of a frost on them, after April 18 20%, and after April 28 10%. The 29 days between the even-odds date and the one-in-ten date is wider than at 82% 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 November 18 in half of years, as early as October 27 one year in ten, and holds off past December 16 one year in ten. A hard freeze of 28°F follows 25 days later, around December 13; in spring the one-in-ten date for 28°F is March 9, 50 days before the 32°F one. The freeze-free season lasts 233 days in a typical year, longer than at 74% of the 103 Oregon stations; it reaches 273 days one year in ten and falls short of 199 one year in ten. On average 31 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 31 days longer, to about April 30, and return around October 25. A 24°F night is unusual: 47% of winters had one.

August is the warmest month at Fort Clatsop Natl Mem, OR, averaging 71°F by day and 53°F at night; December is the coldest at 49°F and 37°F. A freezing night is all but certain in December (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 88% of years and March still brings one in 76% of years and April still brings one in 40% of years.

Warmth for growing adds up to 1,614 growing degree days a year (base 50°F), fewer than at 83% of the 103 Oregon stations. 28% of them (454) have built up by the end of June, and August adds the most, 374.

The nearest other station, Seaside, OR, 10 miles south of Warrenton, has a last frost 3 days later (April 2), a first frost 6 days earlier (November 12), a season 10 days shorter.

Measurable snow is rare here: only 1 of 15 winters from 1991 to 2020 recorded 0.1 inch or more at Fort Clatsop Natl Mem, OR, 1.9 miles away, so there is no typical first-snow date to plan around.

ZIP 97146 is 2 miles from Fort Clatsop Natl Mem, OR, which stands at 42 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 97103 (Astoria). The 2023 USDA Plant Hardiness Zone Map lists ZIP 97146 in zone 9a, the band where the coldest night of the year averaged 20 to 25°F (-6.7 to -3.9°C) over 1991–2020; a zone describes winter lows, not frost dates.