Excessive Heat — Yankton, South Dakota

2023-08-21 to 2023-08-24 · Yankton, South Dakota

Event narrative

Daily afternoon and evening heat indices ranged from 100 to 115 degrees with a maximum heat index of 115 degrees at Automated Weather Observing System site KYKN at Yankton on August 21. A direct fatality occurred in Yankton on the third day of excessive heat when a child was left in a vehicle for an extended time. At the time of the incident, the heat index was 112 degrees with an air temperature of 100 degrees.

Wider weather episode

An immense ridge of high pressure over the Central Plains and Mississippi Valley entrenched heat and high dewpoint air across the region, resulting in daily heat indices from 100 to around 120, with very little recovery during the overnight hours. One direct fatality occurred when an infant was left in a vehicle for an extended period of time during the day in Yankton.

Source: NOAA Storm Events Database, event_id 1138230. Narrative written by the NWS forecast office that issued the report.