Frost Dates for 45810 — Ada, Ohio

Half of springs at Lima Allen Co Airport, OH see their last 32°F night by April 22; 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 28 leaves a 30% risk of a frost on them, after May 2 20%, and after May 7 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 77% of the 148 Ohio stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 22 in half of years, as early as October 7 one year in ten, and holds off past November 4 one year in ten. A hard freeze of 28°F follows 11 days later, around November 2; in spring the one-in-ten date for 28°F is April 25, 12 days before the 32°F one. The freeze-free season lasts 181 days in a typical year, longer than at 53% of the 148 Ohio stations; it reaches 202 days one year in ten and falls short of 161 one year in ten. On average 116 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 2, and return around October 9. Severe cold of 16°F or below comes every winter, usually between December 6 and March 10.

July is the warmest month at Lima Allen Co Airport, OH, averaging 84°F by day and 63°F at night; January is the coldest at 34°F and 20°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 3,226 growing degree days a year (base 50°F), more than at 51% of the 148 Ohio stations. 36% of them (1,156) have built up by the end of June, and July adds the most, 725. Precipitation totals 36.0 inches a year, most in June (4.0") and least in February (1.9"); May to September bring 50% of it.

The nearest other station, Pandora, OH, 14 miles northwest of Ada and 205 feet lower, has a last frost 1 day later (April 23), the same first-frost date, a season 1 day shorter.

The first measurable snow (0.1 inch or more) in Ada usually arrives around November 23, and the last of the season around March 27. Those are the middle dates across the winters of 1991–2020 at Pandora, OH, 14 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 26 days after the last snow.

ZIP 45810 is 12 miles from Lima Allen Co Airport, OH, which stands at 975 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 45810 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.