Frost Dates for 17047 — Loysville, Pennsylvania

Half of springs at Bloserville 1 N, PA see their last 32°F night by April 18; only one in ten is past it by April 3, and one in ten still has one after May 8. Planting tender crops after April 25 leaves a 30% risk of a frost on them, after April 30 20%, and after May 8 10%. The 20 days between the even-odds date and the one-in-ten date is wider than at 98% of the 176 Pennsylvania stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 26 in half of years, as early as October 11 one year in ten, and holds off past November 11 one year in ten. A hard freeze of 28°F follows 14 days later, around November 9; in spring the one-in-ten date for 28°F is April 17, 21 days before the 32°F one. The freeze-free season lasts 191 days in a typical year, longer than at 82% of the 176 Pennsylvania stations; it reaches 212 days one year in ten and falls short of 168 one year in ten. On average 110 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 13 days longer, to about May 1, and return around October 14. Severe cold of 16°F or below comes every winter, usually between December 20 and March 4.

July is the warmest month at Bloserville 1 N, PA, averaging 84°F by day and 63°F at night; January is the coldest at 37°F and 22°F. A freezing night is all but certain in every month from November 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 19% of years.

Warmth for growing adds up to 3,092 growing degree days a year (base 50°F), more than at 59% of the 176 Pennsylvania stations. 33% of them (1,021) have built up by the end of June, and July adds the most, 727. Precipitation totals 43.8 inches a year, most in September (4.5") and least in February (2.4"); May to September bring 47% of it.

The nearest other station, Carlisle Wtp, PA, 15 miles southeast of Loysville and 270 feet lower, has a last frost 5 days later (April 23), a first frost 8 days earlier (October 18), a season 14 days shorter.

The first measurable snow (0.1 inch or more) in Loysville usually arrives around January 9, and the last of the season around March 11. Those are the middle dates across the winters of 1991–2020 at Bloserville 1 N, PA, 7.3 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 38 days after the last snow.

ZIP 17047 is 7 miles from Bloserville 1 N, PA, which stands at 700 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 17241 (Newville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 17047 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°C) over 1991–2020; a zone describes winter lows, not frost dates.