Frost Dates for 98550 — Hoquiam, Washington

Half of springs at Hoquiam Bowerman Airport, WA see their last 32°F night by March 30; only one in ten is past it by February 28, and one in ten still has one after April 25. Planting tender crops after April 9 leaves a 30% risk of a frost on them, after April 16 20%, and after April 25 10%. The 26 days between the even-odds date and the one-in-ten date is wider than at 89% of the 113 Washington 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 14 in half of years, as early as October 22 one year in ten, and holds off past December 9 one year in ten. A hard freeze of 28°F follows 24 days later, around December 8; in spring the one-in-ten date for 28°F is March 23, 33 days before the 32°F one. The freeze-free season lasts 228 days in a typical year, longer than at 81% of the 113 Washington stations; it reaches 265 days one year in ten and falls short of 195 one year in ten. On average 26 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 28 days longer, to about April 27, and return around October 23. Nights of 24°F, cold enough to damage hardier plants, come in 51% of winters and 16°F in 1%.

August is the warmest month at Hoquiam Bowerman Airport, WA, averaging 68°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 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 82% of years and April still brings one in 43% of years.

Warmth for growing adds up to 1,444 growing degree days a year (base 50°F), fewer than at 92% of the 113 Washington stations. 27% of them (384) have built up by the end of June, and August adds the most, 341. Precipitation totals 68.9 inches a year, most in November (11.0") and least in July (0.9"); May to September bring 14% of it.

The nearest other station, Aberdeen, WA, 6 miles southeast of Hoquiam, has a last frost 1 day earlier (March 29), a first frost 1 day later (November 15), a season 6 days longer.

Measurable snow is rare here: only 3 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Aberdeen, WA, 5.9 miles away, so there is no typical first-snow date to plan around.

ZIP 98550 is 4 miles from Hoquiam Bowerman Airport, WA, which stands at 12 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 98550 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.