Frost Dates for 97019 — Corbett, Oregon

Half of springs at Headworks Portland Wtr B, OR see their last 32°F night by March 27; only one in ten is past it by February 26, and one in ten still has one after April 20. Planting tender crops after April 3 leaves a 30% risk of a frost on them, after April 10 20%, and after April 20 10%. The 24 days between the even-odds date and the one-in-ten date is wider than at 60% 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 26 one year in ten, and holds off past December 10 one year in ten. A hard freeze of 28°F follows 21 days later, around December 9; in spring the one-in-ten date for 28°F is March 12, 39 days before the 32°F one. The freeze-free season lasts 239 days in a typical year, longer than at 77% of the 103 Oregon stations; it reaches 274 days one year in ten and falls short of 205 one year in ten. On average 32 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 30 days longer, to about April 26, and return around October 29. Nights of 24°F, cold enough to damage hardier plants, come in 65% of winters and 16°F in 9%.

August is the warmest month at Headworks Portland Wtr B, OR, averaging 78°F by day and 54°F at night; December is the coldest at 43°F and 35°F. A freezing night is all but certain in every month from December to February (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, March still brings one in 76% of years and April still brings one in 33% of years.

Warmth for growing adds up to 1,960 growing degree days a year (base 50°F), fewer than at 64% of the 103 Oregon stations. 27% of them (523) have built up by the end of June, and August adds the most, 493. Precipitation totals 79.1 inches a year, most in December (11.7") and least in July (1.0"); May to September bring 19% of it.

The nearest other station, Skamania Fish Hatchery, WA, 7 miles north of Corbett and 313 feet lower, has a last frost 33 days later (April 29), a first frost 27 days earlier (October 22), a season 62 days shorter.

Measurable snow is rare here: only 5 of 27 winters from 1991 to 2020 recorded 0.1 inch or more at Troutdale, OR, 8 miles away, so there is no typical first-snow date to plan around.

ZIP 97019 is 6 miles from Headworks Portland Wtr B, OR, which stands at 748 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 97055 (Sandy). The 2023 USDA Plant Hardiness Zone Map lists ZIP 97019 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.