Frost Dates for 43302 — Marion, Ohio

Half of springs at Marion 2 N, OH see their last 32°F night by April 25; only one in ten is past it by April 11, and one in ten still has one after May 11. Planting tender crops after May 2 leaves a 30% risk of a frost on them, after May 6 20%, and after May 11 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 5 one year in ten, and holds off past November 2 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 3, 8 days before the 32°F one. The freeze-free season lasts 178 days in a typical year, shorter than at 54% of the 148 Ohio stations; it reaches 198 days one year in ten and falls short of 154 one year in ten. On average 129 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 5, and return around October 8. Severe cold of 16°F or below comes every winter, usually between December 4 and March 13.

July is the warmest month at Marion 2 N, OH, averaging 84°F by day and 63°F at night; January is the coldest at 34°F and 18°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 34% of years.

Warmth for growing adds up to 3,104 growing degree days a year (base 50°F), fewer than at 67% of the 148 Ohio stations. 35% of them (1,087) have built up by the end of June, and July adds the most, 718. Precipitation totals 39.4 inches a year, most in June (4.4") and least in February (2.0"); May to September bring 49% of it.

The nearest other station, Marion Municipal Airport, OH, 4 miles northeast of Marion, has a last frost 1 day earlier (April 24), the same first-frost date.

The first measurable snow (0.1 inch or more) in Marion usually arrives around December 4, and the last of the season around March 14. Those are the middle dates across the winters of 1991–2020 at Marion 2 N, OH, 2 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 43302 is 2 miles from Marion 2 N, OH, which stands at 965 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 43302 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.