Excessive Heat — O'brien, Iowa

2025-08-16 to 2025-08-17 · O'brien, Iowa

Event narrative

Dangerous heat index values peaked as high as 112 degrees near Hartley and 106 degrees at Sheldon on August 16.

Wider weather episode

Heat and moisture pooled near and south of a nearly stationary frontal boundary across eastern South Dakota and southern Minnesota. Daily highs were in the mid 80s to lower 90s with dew point values in the upper 70s to lower 80s, yielding heat index values from 100 to 115 degrees.

Source: NOAA Storm Events Database, event_id 1291162. Narrative written by the NWS forecast office that issued the report.