Frost Dates for 16371 — Youngsville, Pennsylvania

Half of springs at Chandlers Valley 1SE, PA see their last 32°F night by May 22; only one in ten is past it by May 6, and one in ten still has one after June 5. Planting tender crops after May 28 leaves a 30% risk of a frost on them, after May 31 20%, and after June 5 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 September 30 in half of years, as early as September 16 one year in ten, and holds off past October 12 one year in ten. A hard freeze of 28°F follows 11 days later, around October 11; in spring the one-in-ten date for 28°F is May 25, 11 days before the 32°F one. The freeze-free season lasts 131 days in a typical year, shorter than at 98% of the 176 Pennsylvania stations; it reaches 152 days one year in ten and falls short of 109 one year in ten. On average 173 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 June 3, and return around September 18. Severe cold of 16°F or below comes every winter, usually between November 21 and April 1.

July is the warmest month at Chandlers Valley 1SE, PA, averaging 80°F by day and 53°F at night; January is the coldest at 31°F and 13°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, June still brings one in 18% of years.

Warmth for growing adds up to 2,004 growing degree days a year (base 50°F), fewer than at 97% of the 176 Pennsylvania stations. 32% of them (636) have built up by the end of June, and July adds the most, 521. Precipitation totals 48.9 inches a year, most in July (5.5") and least in February (2.5"); May to September bring 47% of it.

The nearest other station, Warren, PA, 9 miles east of Youngsville and 280 feet lower, has a last frost 18 days earlier (May 4), a first frost 21 days later (October 21), a season 37 days longer.

The first measurable snow (0.1 inch or more) in Youngsville usually arrives around November 7, and the last of the season around April 8. Those are the middle dates across the winters of 1991–2020 at Chandlers Valley 1SE, PA, 4.9 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 44 days after the last snow.

ZIP 16371 is 5 miles from Chandlers Valley 1SE, PA, which stands at 1,490 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 16371 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°C) over 1991–2020; a zone describes winter lows, not frost dates.