Excessive Heat — Monona, Iowa

2025-07-27 to 2025-07-28 · Monona, Iowa

Event narrative

Personal weather station measured heat index of 112, 116 and 117 degrees.

Wider weather episode

A prolonged stretch of dangerous heat affected eastern Nebraska and southwest Iowa from Sunday, July 27, through Monday, July 28, 2025. Driven by a strong mid-level ridge centered over the central Plains, the region experienced intense conditions. Heat index values soared to between 111 and 122 degrees, according to observations from ASOS/AWOS sites and personal weather stations. Overnight lows offered little relief, with minimum heat indices in the upper 60s to mid-70s. This persistent lack of cooling overnight compounded heat stress, especially for vulnerable populations.

Source: NOAA Storm Events Database, event_id 1284083. Narrative written by the NWS forecast office that issued the report.