Frost Dates in Indiana

At the middle station of the 117 in Indiana where a freeze comes every year, the last spring frost (50%) is April 21 and the first fall frost October 21, a freeze-free season of 181 days. The last frost is earliest at Evansville (Evansville Museum, IN, March 29) and latest at Fort Wayne (Garrett 1 S, IN, May 2), 34 days apart. The season runs from 159 days at Fort Wayne to 225 at Evansville.

94 of these stations were also in NOAA's previous normals, for 1981–2010. Between the two, the median station's freeze-free season grew 5 days longer, with the last spring frost 1 day earlier and the first fall frost 4 days later; the season lengthened at 79 stations and shortened at 12. The two periods share twenty years, so the change reflects mostly 2011–2020 against 1981–1990.