Frost Dates for 46777 — Ossian, Indiana

Half of springs at Bluffton 6N, IN see their last 32°F night by April 24; only one in ten is past it by April 10, and one in ten still has one after May 9. Planting tender crops after April 30 leaves a 30% risk of a frost on them, after May 3 20%, and after May 9 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 70% of the 125 Indiana 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 3 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 April 27, 12 days before the 32°F one. The freeze-free season lasts 179 days in a typical year, shorter than at 59% of the 125 Indiana stations; it reaches 198 days one year in ten and falls short of 158 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 9 days longer, to about May 3, and return around October 10. Severe cold of 16°F or below comes every winter, usually between December 3 and March 11.

July is the warmest month at Bluffton 6N, IN, averaging 83°F by day and 63°F at night; January is the coldest at 32°F and 17°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 27% of years.

Warmth for growing adds up to 3,091 growing degree days a year (base 50°F), fewer than at 75% of the 125 Indiana stations. 35% of them (1,088) have built up by the end of June, and July adds the most, 711. Precipitation totals 40.1 inches a year, most in May (4.7") and least in February (2.0"); May to September bring 52% of it.

The nearest other station, Fort Wayne International Airport, IN, 7 miles north of Ossian, has the same 50% last-frost date, a first frost 1 day later (October 21), a season 1 day shorter.

The first measurable snow (0.1 inch or more) in Ossian usually arrives around December 5, and the last of the season around March 14. Those are the middle dates across the winters of 1991–2020 at Bluffton 6N, IN, 4.6 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 41 days after the last snow.

ZIP 46777 is 5 miles from Bluffton 6N, IN, which stands at 861 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 46714 (Bluffton). The 2023 USDA Plant Hardiness Zone Map lists ZIP 46777 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.