Frost Dates for 17563 — Peach Bottom, Pennsylvania

Half of springs at Octoraro Lake, PA see their last 32°F night by April 26; only one in ten is past it by April 9, and one in ten still has one after May 10. Planting tender crops after May 2 leaves a 30% risk of a frost on them, after May 5 20%, and after May 10 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 22 in half of years, as early as October 9 one year in ten, and holds off past November 3 one year in ten. A hard freeze of 28°F follows 9 days later, around October 31; in spring the one-in-ten date for 28°F is April 30, 10 days before the 32°F one. The freeze-free season lasts 179 days in a typical year, longer than at 63% of the 176 Pennsylvania stations; it reaches 198 days one year in ten and falls short of 159 one year in ten. On average 125 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 8 days longer, to about May 4, and return around October 13. Severe cold of 16°F or below comes every winter, usually between December 11 and March 7.

July is the warmest month at Octoraro Lake, PA, averaging 85°F by day and 65°F at night; January is the coldest at 39°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 34% of years.

Warmth for growing adds up to 3,280 growing degree days a year (base 50°F), more than at 78% of the 176 Pennsylvania stations. 34% of them (1,110) have built up by the end of June, and July adds the most, 767. Precipitation totals 48.5 inches a year, most in September (5.2") and least in February (2.9"); May to September bring 46% of it.

The nearest other station, Conowingo Dam, MD, 8 miles south of Peach Bottom and 220 feet lower, has a last frost 23 days earlier (April 3), a first frost 15 days later (November 6), a season 38 days longer.

The first measurable snow (0.1 inch or more) in Peach Bottom usually arrives around January 9, and the last of the season around March 4. Those are the middle dates across the winters of 1991–2020 at Conowingo Dam, MD, 7.7 miles away: half of years saw snow earlier, half later. Snow fell in 82% of those winters. The last 32°F night of spring typically comes 53 days after the last snow.

ZIP 17563 is 7 miles from Octoraro Lake, PA, which stands at 260 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 6 other ZIP codes share the station; its figures are presented in full for 19363 (Oxford). The 2023 USDA Plant Hardiness Zone Map lists ZIP 17563 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.