Frost Dates for 15131 — White Oak, Pennsylvania

Half of springs at Mckeesport, PA see their last 32°F night by May 2; only one in ten is past it by April 17, and one in ten still has one after May 20. Planting tender crops after May 10 leaves a 30% risk of a frost on them, after May 14 20%, and after May 20 10%. The 18 days between the even-odds date and the one-in-ten date is wider than at 70% 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 1 one year in ten, and holds off past November 3 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 May 10, 10 days before the 32°F one. The freeze-free season lasts 170 days in a typical year, shorter than at 60% of the 176 Pennsylvania stations; it reaches 192 days one year in ten and falls short of 144 one year in ten. On average 124 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 12, and return around October 7. Severe cold of 16°F or below comes every winter, usually between December 10 and March 10.

July is the warmest month at Mckeesport, PA, averaging 85°F by day and 61°F at night; January is the coldest at 39°F and 21°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 54% of years.

Warmth for growing adds up to 3,104 growing degree days a year (base 50°F), more than at 60% of the 176 Pennsylvania stations. 34% of them (1,066) have built up by the end of June, and July adds the most, 714. Precipitation totals 42.4 inches a year, most in June (5.0") and least in February (2.5"); May to September bring 47% of it.

The nearest other station, Braddock Lock 2, PA, 4 miles northwest of White Oak, has a last frost 27 days earlier (April 5), a first frost 21 days later (November 10), a season 49 days longer.

The first measurable snow (0.1 inch or more) in White Oak usually arrives around December 22, and the last of the season around February 22. Those are the middle dates across the winters of 1991–2020 at Braddock Lock 2, PA, 4.3 miles away: half of years saw snow earlier, half later. Snow fell in 81% of those winters. The last 32°F night of spring typically comes 69 days after the last snow.

ZIP 15131 is 3 miles from Mckeesport, PA, which stands at 740 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 15132 (Mckeesport). The 2023 USDA Plant Hardiness Zone Map lists ZIP 15131 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.