Frost Dates for 15825 — Brookville, Pennsylvania

Half of springs at Dubois Jefferson Co Airport, PA see their last 32°F night by May 6; only one in ten is past it by April 19, and one in ten still has one after May 23. Planting tender crops after May 13 leaves a 30% risk of a frost on them, after May 17 20%, and after May 23 10%. The 17 days between the even-odds date and the one-in-ten date is wider than at 50% of the 176 Pennsylvania stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 14 in half of years, as early as September 29 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 14 days later, around October 28; in spring the one-in-ten date for 28°F is May 13, 10 days before the 32°F one. The freeze-free season lasts 160 days in a typical year, shorter than at 73% of the 176 Pennsylvania stations; it reaches 183 days one year in ten and falls short of 139 one year in ten. On average 138 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 May 18, and return around October 1. Severe cold of 16°F or below comes every winter, usually between December 1 and March 21.

July is the warmest month at Dubois Jefferson Co Airport, PA, averaging 79°F by day and 59°F at night; January is the coldest at 32°F and 17°F. A freezing night is all but certain in every month from November 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 63% of years.

Warmth for growing adds up to 2,428 growing degree days a year (base 50°F), fewer than at 81% of the 176 Pennsylvania stations. 34% of them (816) have built up by the end of June, and July adds the most, 591. Precipitation totals 42.6 inches a year, most in June (4.7") and least in February (2.4"); May to September bring 49% of it.

The nearest other station, Cooksburg 2 NW, PA, 16 miles northwest of Brookville and 364 feet lower, has a last frost 7 days later (May 13), a first frost 7 days earlier (October 7), a season 17 days shorter.

The first measurable snow (0.1 inch or more) in Brookville usually arrives around November 30, and the last of the season around March 23. Those are the middle dates across the winters of 1991–2020 at Clarion 3 SW, PA, 19.4 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 15825 is 9 miles from Dubois Jefferson Co Airport, PA, which stands at 1,814 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station; its figures are presented in full for 15801 (Du Bois). The 2023 USDA Plant Hardiness Zone Map lists ZIP 15825 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.