Heat — Spencer, Indiana

2025-07-16 to 2025-07-17 · Spencer, Indiana

Wider weather episode

An extended heat wave across the Quad State region occurred from mid to late July. On the synoptic scale, at 500mb, a 594dam ridge was present across the Southeast U.S., with the ridge building northward to include the Ohio Valley and Great Lakes by July 22nd-23rd. The Quad State was initially on the edge of the ridge from the 17th-21st, resulting in greater coverage of showers and thunderstorms. Heat issues continued through the end of July.

High temperatures in the low to mid 90s combined with very high humidity (dew points in the mid to upper 70s) produced heat index values in the 100-105 range in Southwest Indiana on July 16th-17th and again on the 20th. Some relief from the heat came for Southwest Indiana on the 19th and 21st due to widespread showers/storms and cloud cover.

For the entirety of the mid-late month heatwave, Evansville, IN experienced 18 consecutive days with a 75 degree dew point, their second longest streak on record (dating back to 1948). The highest heat index in Southwest Indiana for the third week of July was 105 at the Evansville Regional Airport ASOS on the 20th.

Source: NOAA Storm Events Database, event_id 1290077. Narrative written by the NWS forecast office that issued the report.