Frost Dates for 98660 — Vancouver, Washington

Half of springs at Vancouver 4 NNE, WA see their last 32°F night by April 26; only one in ten is past it by April 7, 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 18 in half of years, as early as October 1 one year in ten, and holds off past November 8 one year in ten. A hard freeze of 28°F follows 17 days later, around November 4; in spring the one-in-ten date for 28°F is April 20, 20 days before the 32°F one. The freeze-free season lasts 177 days in a typical year, shorter than at 60% of the 113 Washington stations; it reaches 206 days one year in ten and falls short of 153 one year in ten. On average 66 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 14 days longer, to about May 10, and return around October 1. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 54%.

August is the warmest month at Vancouver 4 NNE, WA, averaging 79°F by day and 52°F at night; December is the coldest at 45°F and 32°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 32% of years.

Warmth for growing adds up to 1,916 growing degree days a year (base 50°F), fewer than at 54% of the 113 Washington stations. 28% of them (540) have built up by the end of June, and August adds the most, 482. Precipitation totals 42.2 inches a year, most in December (6.8") and least in July (0.5"); May to September bring 17% of it.

The nearest other station, Vancouver Pearson Airport, WA, 3 miles southeast of Vancouver and 180 feet lower, has a last frost 28 days earlier (March 29), a first frost 22 days later (November 9), a season 46 days longer.

Measurable snow is rare here: only 11 of 27 winters from 1991 to 2020 recorded 0.1 inch or more at Vancouver 4 NNE, WA, 2.6 miles away, so there is no typical first-snow date to plan around.

ZIP 98660 is 3 miles from Vancouver 4 NNE, WA, which stands at 210 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station; its figures are presented in full for 98682 (Vancouver). The 2023 USDA Plant Hardiness Zone Map lists ZIP 98660 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.