Frost Dates for 47901 — Lafayette, Indiana

Half of springs at Lafayette Purdue Univ Airport, IN see their last 32°F night by April 26; only one in ten is past it by April 11, and one in ten still has one after May 14. Planting tender crops after May 3 leaves a 30% risk of a frost on them, after May 7 20%, and after May 14 10%. The 18 days between the even-odds date and the one-in-ten date is wider than at 84% of the 125 Indiana stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 18 in half of years, as early as October 4 one year in ten, and holds off past October 31 one year in ten. A hard freeze of 28°F follows 10 days later, around October 28; in spring the one-in-ten date for 28°F is May 1, 13 days before the 32°F one. The freeze-free season lasts 173 days in a typical year, shorter than at 77% of the 125 Indiana stations; it reaches 192 days one year in ten and falls short of 152 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 11 days longer, to about May 7, and return around October 7. Severe cold of 16°F or below comes every winter, usually between December 1 and March 11.

July is the warmest month at Lafayette Purdue Univ Airport, IN, averaging 84°F by day and 63°F at night; January is the coldest at 33°F and 18°F. A freezing night is all but certain in every month from October 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 38% of years.

Warmth for growing adds up to 3,277 growing degree days a year (base 50°F), fewer than at 57% of the 125 Indiana stations. 36% of them (1,168) have built up by the end of June, and July adds the most, 732. Precipitation totals 37.0 inches a year, most in June (4.6") and least in February (1.8"); May to September bring 50% of it.

The nearest other station, W Lafayette 6 NW, IN, 7 miles northwest of Lafayette, has the same 50% last-frost date, a first frost 6 days earlier (October 12), a season 4 days shorter.

The first measurable snow (0.1 inch or more) in Lafayette 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, 6.6 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 42 days after the last snow.

ZIP 47901 is 3 miles from Lafayette Purdue Univ Airport, IN, which stands at 599 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 47905 (Lafayette). The 2023 USDA Plant Hardiness Zone Map lists ZIP 47901 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.