Frost Dates for 97138 — Seaside, Oregon

Half of springs at Seaside, OR see their last 32°F night by April 2; only one in ten is past it by March 4, and one in ten still has one after April 29. Planting tender crops after April 11 leaves a 30% risk of a frost on them, after April 20 20%, and after April 29 10%. The 27 days between the even-odds date and the one-in-ten date is wider than at 75% 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 12 in half of years, as early as October 18 one year in ten, and holds off past December 6 one year in ten. A hard freeze of 28°F follows 22 days later, around December 4; in spring the one-in-ten date for 28°F is March 31, 29 days before the 32°F one. The freeze-free season lasts 223 days in a typical year, longer than at 68% of the 103 Oregon stations; it reaches 264 days one year in ten and falls short of 189 one year in ten. On average 29 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 27 days longer, to about April 29, and return around October 20. Nights of 24°F, cold enough to damage hardier plants, come in 59% of winters and 16°F in 1%.

August is the warmest month at Seaside, OR, averaging 66°F by day and 54°F at night; December is the coldest at 51°F and 39°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 89% of years and March still brings one in 83% of years and April still brings one in 50% of years.

Warmth for growing adds up to 1,402 growing degree days a year (base 50°F), fewer than at 93% of the 103 Oregon stations. 27% of them (383) have built up by the end of June, and August adds the most, 308. Precipitation totals 76.8 inches a year, most in November (12.0") and least in July (1.0"); May to September bring 15% of it.

The nearest other station, Fort Clatsop Natl Mem, OR, 15 miles north of Seaside, has a last frost 3 days earlier (March 30), a first frost 6 days later (November 18), a season 10 days longer.

Measurable snow is rare here: only 0 of 27 winters from 1991 to 2020 recorded 0.1 inch or more at Seaside, OR, 6.7 miles away, so there is no typical first-snow date to plan around.

ZIP 97138 is 7 miles from Seaside, OR, which stands at 10 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 97138 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.