Frost Dates for 15717 — Blairsville, Pennsylvania

Half of springs at Loyalhanna Lake, PA see their last 32°F night by May 2; only one in ten is past it by April 18, and one in ten still has one after May 18. Planting tender crops after May 9 leaves a 30% risk of a frost on them, after May 13 20%, and after May 18 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 51% of the 176 Pennsylvania stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 14 in half of years, as early as October 2 one year in ten, and holds off past October 27 one year in ten. A hard freeze of 28°F follows 11 days later, around October 25; in spring the one-in-ten date for 28°F is May 8, 10 days before the 32°F one. The freeze-free season lasts 163 days in a typical year, shorter than at 70% of the 176 Pennsylvania stations; it reaches 183 days one year in ten and falls short of 143 one year in ten. On average 130 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 14, and return around October 3. Severe cold of 16°F or below comes every winter, usually between November 27 and March 16.

July is the warmest month at Loyalhanna Lake, PA, averaging 83°F by day and 59°F at night; January is the coldest at 37°F and 19°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 56% of years.

Warmth for growing adds up to 2,771 growing degree days a year (base 50°F), fewer than at 63% of the 176 Pennsylvania stations. 34% of them (935) have built up by the end of June, and July adds the most, 656. Precipitation totals 43.5 inches a year, most in August (4.6") and least in February (2.5"); May to September bring 48% of it.

The nearest other station, Indiana 3 SE, PA, 12 miles northeast of Blairsville, has a last frost 6 days later (May 8), a first frost 1 day earlier (October 13), a season 6 days shorter.

The first measurable snow (0.1 inch or more) in Blairsville usually arrives around December 6, and the last of the season around March 14. Those are the middle dates across the winters of 1991–2020 at Loyalhanna Lake, PA, 10.8 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 49 days after the last snow.

ZIP 15717 is 11 miles from Loyalhanna Lake, PA, which stands at 990 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 15717 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.