Frost Dates for 17837 — Lewisburg, Pennsylvania

Half of springs at Lewisburg, PA see their last 32°F night by April 26; only one in ten is past it by April 13, and one in ten still has one after May 11. Planting tender crops after May 2 leaves a 30% risk of a frost on them, after May 5 20%, and after May 11 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 72% of the 176 Pennsylvania stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 20 in half of years, as early as October 5 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 12 days later, around November 1; in spring the one-in-ten date for 28°F is April 28, 13 days before the 32°F one. The freeze-free season lasts 176 days in a typical year, longer than at 52% of the 176 Pennsylvania stations; it reaches 195 days one year in ten and falls short of 156 one year in ten. On average 133 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 10 days longer, to about May 6, and return around October 7. Severe cold of 16°F or below comes every winter, usually between December 6 and March 10.

July is the warmest month at Lewisburg, PA, averaging 84°F by day and 62°F at night; January is the coldest at 35°F and 19°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 2,923 growing degree days a year (base 50°F), fewer than at 53% of the 176 Pennsylvania stations. 34% of them (990) have built up by the end of June, and July adds the most, 710. Precipitation totals 43.9 inches a year, most in July (4.5") and least in February (2.4"); May to September bring 47% of it.

The nearest other station, Sunbury, PA, 10 miles southeast of Lewisburg, has a last frost 4 days later (April 30), a first frost 7 days earlier (October 13), a season 10 days shorter.

The first measurable snow (0.1 inch or more) in Lewisburg usually arrives around December 1, and the last of the season around March 21. Those are the middle dates across the winters of 1991–2020 at Lewisburg, PA, 2.2 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 36 days after the last snow.

ZIP 17837 is 2 miles from Lewisburg, PA, which stands at 500 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 17837 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.