Frost Dates for 15437 — Farmington, Pennsylvania

Half of springs at Chalk Hill 2 ENE, PA see their last 32°F night by May 19; only one in ten is past it by April 30, and one in ten still has one after June 2. Planting tender crops after May 25 leaves a 30% risk of a frost on them, after May 29 20%, and after June 2 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 86% of the 176 Pennsylvania stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 1 in half of years, as early as September 18 one year in ten, and holds off past October 13 one year in ten. A hard freeze of 28°F follows 9 days later, around October 10; in spring the one-in-ten date for 28°F is May 22, 11 days before the 32°F one. The freeze-free season lasts 135 days in a typical year, shorter than at 98% of the 176 Pennsylvania stations; it reaches 157 days one year in ten and falls short of 114 one year in ten. On average 138 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 12 days longer, to about May 31, and return around September 21. Severe cold of 16°F or below comes every winter, usually between November 13 and March 29.

July is the warmest month at Chalk Hill 2 ENE, PA, averaging 79°F by day and 56°F at night; January is the coldest at 34°F and 15°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 85% of years and June still brings one in 15% of years.

Warmth for growing adds up to 2,131 growing degree days a year (base 50°F), fewer than at 91% of the 176 Pennsylvania stations. 34% of them (732) have built up by the end of June, and July adds the most, 529. Precipitation totals 55.6 inches a year, most in June (5.7") and least in October (3.8"); May to September bring 45% of it.

The nearest other station, Uniontown 1 NE, PA, 11 miles northwest of Farmington and 1,024 feet lower, has a last frost 19 days earlier (April 30), a first frost 17 days later (October 18), a season 36 days longer.

The first measurable snow (0.1 inch or more) in Farmington usually arrives around November 7, and the last of the season around April 10. Those are the middle dates across the winters of 1991–2020 at Chalk Hill 2 ENE, PA, 3.8 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 39 days after the last snow.

ZIP 15437 is 4 miles from Chalk Hill 2 ENE, PA, which stands at 1,980 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 15437 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.