Frost Dates for 97101 — Amity, Oregon

Half of springs at Mcminnville Municipal Airport, OR see their last 32°F night by April 15; only one in ten is past it by March 18, and one in ten still has one after May 6. Planting tender crops after April 26 leaves a 30% risk of a frost on them, after April 30 20%, and after May 6 10%. The 21 days between the even-odds date and the one-in-ten date is narrower than at 55% 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 October 26 in half of years, as early as October 5 one year in ten, and holds off past November 19 one year in ten. A hard freeze of 28°F follows 21 days later, around November 16; in spring the one-in-ten date for 28°F is April 8, 28 days before the 32°F one. The freeze-free season lasts 195 days in a typical year, shorter than at 52% of the 103 Oregon stations; it reaches 230 days one year in ten and falls short of 162 one year in ten. On average 47 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 23 days longer, to about May 8, and return around October 7. Nights of 24°F, cold enough to damage hardier plants, come in 88% of winters and 16°F in 15%.

August is the warmest month at Mcminnville Municipal Airport, OR, averaging 83°F by day and 52°F at night; December is the coldest at 47°F and 34°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 67% of years and May still brings one in 18% of years.

Warmth for growing adds up to 2,240 growing degree days a year (base 50°F), fewer than at 51% of the 103 Oregon stations. 28% of them (625) have built up by the end of June, and August adds the most, 543. Precipitation totals 37.8 inches a year, most in December (6.5") and least in July (0.3"); May to September bring 14% of it.

The nearest other station, Mc Minnville, OR, 9 miles north of Amity, has a last frost 10 days earlier (April 5), a first frost 12 days later (November 7), a season 21 days longer.

Measurable snow is rare here: only 7 of 19 winters from 1991 to 2020 recorded 0.1 inch or more at Mc Minnville, OR, 9 miles away, so there is no typical first-snow date to plan around.

ZIP 97101 is 8 miles from Mcminnville Municipal Airport, OR, which stands at 159 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 97114 (Dayton). The 2023 USDA Plant Hardiness Zone Map lists ZIP 97101 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.