Frost Dates for 19510 — Blandon, Pennsylvania

Half of springs at Reading 4 NNW, PA see their last 32°F night by April 10; only one in ten is past it by March 29, and one in ten still has one after April 26. Planting tender crops after April 17 leaves a 30% risk of a frost on them, after April 21 20%, and after April 26 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 October 31 in half of years, as early as October 14 one year in ten, and holds off past November 13 one year in ten. A hard freeze of 28°F follows 11 days later, around November 11; in spring the one-in-ten date for 28°F is April 12, 14 days before the 32°F one. The freeze-free season lasts 202 days in a typical year, longer than at 90% of the 176 Pennsylvania stations; it reaches 221 days one year in ten and falls short of 181 one year in ten. On average 106 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 15 days longer, to about April 25, and return around October 18. Severe cold of 16°F or below comes every winter, usually between December 24 and February 28.

July is the warmest month at Reading 4 NNW, PA, averaging 86°F by day and 66°F at night; January is the coldest at 39°F and 23°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 81% of years.

Warmth for growing adds up to 3,566 growing degree days a year (base 50°F), more than at 93% of the 176 Pennsylvania stations. 34% of them (1,217) have built up by the end of June, and July adds the most, 803.

The nearest other station, Reading Spaatz Field, PA, 7 miles southwest of Blandon, has a last frost 4 days later (April 14), a first frost 2 days earlier (October 29), a season 5 days shorter.

The first measurable snow (0.1 inch or more) in Blandon usually arrives around December 30, and the last of the season around March 16. Those are the middle dates across the winters of 1991–2020 at Reading 4 NNW, PA, 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 25 days after the last snow.

ZIP 19510 is 3 miles from Reading 4 NNW, PA, which stands at 360 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 19522 (Fleetwood). The 2023 USDA Plant Hardiness Zone Map lists ZIP 19510 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°C) over 1991–2020; a zone describes winter lows, not frost dates.