Frost Dates for 17512 — Columbia, Pennsylvania

Half of springs at Landisville 2 NW, PA see their last 32°F night by April 30; only one in ten is past it by April 16, and one in ten still has one after May 13. Planting tender crops after May 5 leaves a 30% risk of a frost on them, after May 8 20%, and after May 13 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 94% of the 176 Pennsylvania stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 10 in half of years, as early as September 29 one year in ten, and holds off past October 26 one year in ten. A hard freeze of 28°F follows 14 days later, around October 24; in spring the one-in-ten date for 28°F is May 2, 11 days before the 32°F one. The freeze-free season lasts 162 days in a typical year, shorter than at 72% of the 176 Pennsylvania stations; it reaches 182 days one year in ten and falls short of 144 one year in ten. On average 122 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 9 days longer, to about May 9, and return around September 30. Severe cold of 16°F or below comes every winter, usually between December 1 and March 14.

July is the warmest month at Landisville 2 NW, PA, averaging 85°F by day and 61°F at night; January is the coldest at 37°F and 19°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 45% of years.

Warmth for growing adds up to 3,008 growing degree days a year (base 50°F), more than at 52% of the 176 Pennsylvania stations. 34% of them (1,033) have built up by the end of June, and July adds the most, 710. Precipitation totals 45.1 inches a year, most in July (4.8") and least in February (2.4"); May to September bring 48% of it.

The nearest other station, Safe Harbor Dam, PA, 9 miles southeast of Columbia and 165 feet lower, has a last frost 29 days earlier (April 1), a first frost 31 days later (November 10), a season 59 days longer.

The first measurable snow (0.1 inch or more) in Columbia usually arrives around December 10, and the last of the season around March 19. Those are the middle dates across the winters of 1991–2020 at Landisville 2 NW, PA, 6.6 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 42 days after the last snow.

ZIP 17512 is 7 miles from Landisville 2 NW, PA, which stands at 360 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station; its figures are presented in full for 17545 (Manheim). The 2023 USDA Plant Hardiness Zone Map lists ZIP 17512 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.