Frost Dates for 45304 — Arcanum, Ohio

Half of springs at Greenville Wtp, OH see their last 32°F night by April 21; only one in ten is past it by April 7, and one in ten still has one after May 7. Planting tender crops after April 27 leaves a 30% risk of a frost on them, after May 1 20%, and after May 7 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 53% of the 148 Ohio 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 6 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 11 days later, around October 31; in spring the one-in-ten date for 28°F is April 24, 13 days before the 32°F one. The freeze-free season lasts 180 days in a typical year, longer than at 50% of the 148 Ohio stations; it reaches 201 days one year in ten and falls short of 160 one year in ten. On average 126 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 1, and return around October 8. Severe cold of 16°F or below comes every winter, usually between December 5 and March 9.

July is the warmest month at Greenville Wtp, OH, averaging 85°F by day and 64°F at night; January is the coldest at 35°F and 19°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 23% of years.

Warmth for growing adds up to 3,360 growing degree days a year (base 50°F), more than at 65% of the 148 Ohio stations. 36% of them (1,221) have built up by the end of June, and July adds the most, 747. Precipitation totals 40.3 inches a year, most in June (4.4") and least in February (2.2"); May to September bring 47% of it.

The nearest other station, Dayton International Airport, OH, 18 miles east of Arcanum, has a last frost 5 days earlier (April 16), a first frost 8 days later (October 28), a season 14 days longer.

The first measurable snow (0.1 inch or more) in Arcanum usually arrives around December 9, and the last of the season around March 14. Those are the middle dates across the winters of 1991–2020 at Greenville Wtp, OH, 9.8 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 38 days after the last snow.

ZIP 45304 is 10 miles from Greenville Wtp, OH, which stands at 1,030 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 45331 (Greenville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 45304 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.