Frost Dates for 47970 — Otterbein, Indiana

Half of springs at W Lafayette 6 NW, IN see their last 32°F night by April 26; only one in ten is past it by April 12, 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 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 12 in half of years, as early as September 27 one year in ten, and holds off past October 27 one year in ten. A hard freeze of 28°F follows 13 days later, around October 25; in spring the one-in-ten date for 28°F is April 30, 11 days before the 32°F one. The freeze-free season lasts 169 days in a typical year, shorter than at 91% of the 125 Indiana stations; it reaches 189 days one year in ten and falls short of 147 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 6, and return around September 30. Severe cold of 16°F or below comes every winter, usually between November 27 and March 13.

July is the warmest month at W Lafayette 6 NW, IN, averaging 83°F by day and 63°F at night; January is the coldest at 32°F and 16°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 36% of years.

Warmth for growing adds up to 3,154 growing degree days a year (base 50°F), fewer than at 67% of the 125 Indiana stations. 37% of them (1,153) have built up by the end of June, and July adds the most, 705. Precipitation totals 39.7 inches a year, most in June (4.9") and least in February (1.9"); May to September bring 52% of it.

The nearest other station, Lafayette Purdue Univ Airport, IN, 10 miles southeast of Otterbein, has the same 50% last-frost date, a first frost 6 days later (October 18), a season 4 days longer.

The first measurable snow (0.1 inch or more) in Otterbein usually arrives around December 4, and the last of the season around March 15. Those are the middle dates across the winters of 1991–2020 at W Lafayette 6 NW, IN, 6.2 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 47970 is 6 miles from W Lafayette 6 NW, IN, which stands at 708 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 47906 (West Lafayette). The 2023 USDA Plant Hardiness Zone Map lists ZIP 47970 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.