Frost Dates for 98221 — Anacortes, Washington

Half of springs at Anacortes, WA see their last 32°F night by March 8; only one in ten is past it by February 17, and one in ten still has one after March 28. Planting tender crops after March 16 leaves a 30% risk of a frost on them, after March 21 20%, and after March 28 10%. The 20 days between the even-odds date and the one-in-ten date is wider than at 52% of the 113 Washington stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 20 in half of years, as early as November 1 one year in ten, and holds off past December 11 one year in ten. A hard freeze of 28°F follows 15 days later, around December 5; in spring the one-in-ten date for 28°F is March 5, 23 days before the 32°F one. The freeze-free season lasts 255 days in a typical year, longer than at 96% of the 113 Washington stations; it reaches 288 days one year in ten and falls short of 228 one year in ten. On average 30 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 24 days longer, to about April 1, and return around November 2. Nights of 24°F, cold enough to damage hardier plants, come in 76% of winters and 16°F in 8%.

August is the warmest month at Anacortes, WA, averaging 75°F by day and 54°F at night; December is the coldest at 47°F and 37°F. A freezing night is all but certain in every month from December to February (a 90% chance or more). From April to October the chance of a 32°F night stays under 10% each month. In spring, March still brings one in 67% of years.

Warmth for growing adds up to 2,013 growing degree days a year (base 50°F), more than at 53% of the 113 Washington stations. 32% of them (642) have built up by the end of June, and August adds the most, 454. Precipitation totals 29.2 inches a year, most in November (4.4") and least in July (0.8"); May to September bring 25% of it.

The nearest other station, Whidbey Island NAS, WA, 10 miles south of Anacortes, has a last frost 5 days later (March 13), a first frost 6 days earlier (November 14), a season 11 days shorter.

Measurable snow is rare here: only 6 of 18 winters from 1991 to 2020 recorded 0.1 inch or more at Anacortes, WA, 1.2 miles away, so there is no typical first-snow date to plan around.

ZIP 98221 is 1 mile from Anacortes, WA, which stands at 20 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 98221 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.