Frost Dates for 18407 — Carbondale, Pennsylvania

Half of springs at Pleasant Mt 1 W, PA see their last 32°F night by May 14; only one in ten is past it by April 30, and one in ten still has one after May 29. Planting tender crops after May 20 leaves a 30% risk of a frost on them, after May 24 20%, and after May 29 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 1 in half of years, as early as September 21 one year in ten, and holds off past October 15 one year in ten. A hard freeze of 28°F follows 11 days later, around October 12; in spring the one-in-ten date for 28°F is May 18, 11 days before the 32°F one. The freeze-free season lasts 140 days in a typical year, shorter than at 94% of the 176 Pennsylvania stations; it reaches 158 days one year in ten and falls short of 121 one year in ten. On average 169 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 27, and return around September 23. Severe cold of 16°F or below comes every winter, usually between November 19 and March 31.

July is the warmest month at Pleasant Mt 1 W, PA, averaging 77°F by day and 56°F at night; January is the coldest at 29°F and 12°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 86% of years.

Warmth for growing adds up to 1,887 growing degree days a year (base 50°F), fewer than at 98% of the 176 Pennsylvania stations. 31% of them (577) have built up by the end of June, and July adds the most, 516. Precipitation totals 51.5 inches a year, most in June (5.0") and least in February (3.0"); May to September bring 47% of it.

The nearest other station, Hawley 1 E, PA, 19 miles east of Carbondale and 910 feet lower, has a last frost 4 days earlier (May 10), a first frost 3 days later (October 4), a season 6 days longer.

The first measurable snow (0.1 inch or more) in Carbondale usually arrives around November 13, and the last of the season around April 5. Those are the middle dates across the winters of 1991–2020 at Pleasant Mt 1 W, PA, 11.3 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 39 days after the last snow.

ZIP 18407 is 11 miles from Pleasant Mt 1 W, PA, which stands at 1,800 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 18407 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°C) over 1991–2020; a zone describes winter lows, not frost dates.