Frost Dates for 46390 — Wanatah, Indiana

Half of springs at Wanatah 2 WNW, IN see their last 32°F night by April 29; only one in ten is past it by April 15, and one in ten still has one after May 14. Planting tender crops after May 5 leaves a 30% risk of a frost on them, after May 9 20%, and after May 14 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 13 in half of years, as early as October 1 one year in ten, and holds off past October 27 one year in ten. A hard freeze of 28°F follows 12 days later, around October 25; in spring the one-in-ten date for 28°F is May 3, 11 days before the 32°F one. The freeze-free season lasts 166 days in a typical year, shorter than at 96% of the 125 Indiana stations; it reaches 186 days one year in ten and falls short of 145 one year in ten. On average 147 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 9, and return around October 1. Severe cold of 16°F or below comes every winter, usually between December 1 and March 15.

July is the warmest month at Wanatah 2 WNW, IN, averaging 83°F by day and 62°F at night; January is the coldest at 32°F and 15°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 43% of years.

Warmth for growing adds up to 2,944 growing degree days a year (base 50°F), fewer than at 94% of the 125 Indiana stations. 35% of them (1,036) have built up by the end of June, and July adds the most, 694. Precipitation totals 39.6 inches a year, most in June (4.7") and least in February (1.9"); May to September bring 52% of it.

The nearest other station, Valparaiso Porter Co Municipal Airport, IN, 7 miles west of Wanatah, has a last frost 9 days earlier (April 20), a first frost 13 days later (October 26), a season 21 days longer.

The first measurable snow (0.1 inch or more) in Wanatah usually arrives around November 25, and the last of the season around March 29. Those are the middle dates across the winters of 1991–2020 at Wanatah 2 WNW, IN, 3 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 31 days after the last snow.

ZIP 46390 is 3 miles from Wanatah 2 WNW, IN, which stands at 735 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 46390 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°C) over 1991–2020; a zone describes winter lows, not frost dates.