Frost Dates for 16222 — Dayton, Pennsylvania

Half of springs at Putneyville 2 SE Dam, PA see their last 32°F night by May 10; only one in ten is past it by April 24, and one in ten still has one after May 28. Planting tender crops after May 19 leaves a 30% risk of a frost on them, after May 23 20%, and after May 28 10%. The 18 days between the even-odds date and the one-in-ten date is wider than at 70% of the 176 Pennsylvania stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 12 in half of years, as early as September 30 one year in ten, and holds off past October 27 one year in ten. A hard freeze of 28°F follows 14 days later, around October 26; in spring the one-in-ten date for 28°F is May 19, 9 days before the 32°F one. The freeze-free season lasts 155 days in a typical year, shorter than at 82% of the 176 Pennsylvania stations; it reaches 177 days one year in ten and falls short of 131 one year in ten. On average 152 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 11 days longer, to about May 21, and return around October 1. Severe cold of 16°F or below comes every winter, usually between December 1 and March 23.

July is the warmest month at Putneyville 2 SE Dam, PA, averaging 82°F by day and 58°F at night; January is the coldest at 35°F and 17°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 72% of years.

Warmth for growing adds up to 2,597 growing degree days a year (base 50°F), fewer than at 72% of the 176 Pennsylvania stations. 34% of them (874) have built up by the end of June, and July adds the most, 625. Precipitation totals 45.9 inches a year, most in June (4.8") and least in February (2.9"); May to September bring 47% of it.

The nearest other station, Ford City 4 S Dam, PA, 18 miles southwest of Dayton and 350 feet lower, has a last frost 6 days earlier (May 4), a first frost 4 days later (October 16), a season 9 days longer.

The first measurable snow (0.1 inch or more) in Dayton usually arrives around December 5, and the last of the season around March 22. Those are the middle dates across the winters of 1991–2020 at Putneyville 2 SE Dam, PA, 4.1 miles away: half of years saw snow earlier, half later. Snow fell in 96% of those winters. The last 32°F night of spring typically comes 49 days after the last snow.

ZIP 16222 is 4 miles from Putneyville 2 SE Dam, PA, which stands at 1,280 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 16242 (New Bethlehem). The 2023 USDA Plant Hardiness Zone Map lists ZIP 16222 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°C) over 1991–2020; a zone describes winter lows, not frost dates.