Frost Dates for 19038 — Glenside, Pennsylvania

Half of springs at Willow Grove NAS, PA see their last 32°F night by April 11; only one in ten is past it by March 29, and one in ten still has one after April 27. Planting tender crops after April 17 leaves a 30% risk of a frost on them, after April 21 20%, and after April 27 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 51% of the 176 Pennsylvania stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 1 in half of years, as early as October 17 one year in ten, and holds off past November 17 one year in ten. A hard freeze of 28°F follows 12 days later, around November 13; in spring the one-in-ten date for 28°F is April 12, 15 days before the 32°F one. The freeze-free season lasts 205 days in a typical year, longer than at 92% of the 176 Pennsylvania stations; it reaches 226 days one year in ten and falls short of 182 one year in ten. On average 92 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 April 24, and return around October 21. Severe cold of 16°F or below comes every winter, usually between December 25 and February 24.

July is the warmest month at Willow Grove NAS, PA, averaging 85°F by day and 67°F at night; January is the coldest at 40°F and 24°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 82% of years.

Warmth for growing adds up to 3,507 growing degree days a year (base 50°F), more than at 90% of the 176 Pennsylvania stations. 34% of them (1,192) have built up by the end of June, and July adds the most, 804.

The nearest other station, Philadelphia NE Airport, PA, 8 miles east of Glenside and 261 feet lower, has a last frost 7 days earlier (April 4), a first frost 6 days later (November 7), a season 11 days longer.

The first measurable snow (0.1 inch or more) in Glenside usually arrives around December 26, and the last of the season around March 21. Those are the middle dates across the winters of 1991–2020 at Willow Grove NAS, PA, 6.7 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 21 days after the last snow.

ZIP 19038 is 7 miles from Willow Grove NAS, PA, which stands at 361 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 12 other ZIP codes share the station; its figures are presented in full for 18974 (Warminster). The 2023 USDA Plant Hardiness Zone Map lists ZIP 19038 in zone 7b, the band where the coldest night of the year averaged 5 to 10°F (-15.0 to -12.2°C) over 1991–2020; a zone describes winter lows, not frost dates.