# Chicago extreme heat wave

> Live situation record from CLSTR: https://clstr.news/situations/chicago-extreme-heat-wave
> Updated: 2026-09-03T16:14:12.000Z. Sources: 6. Developments: 2.

Chicago has been impacted by a significant heat wave characterized by dangerous temperatures and high humidity. A heat dome has driven temperatures approximately 10 degrees above the seasonal average, with heat index values expected to exceed 100 degrees.

This late-season event is considered unusual by experts. The extreme weather follows a summer that included two previous heat waves in July. The heat has already resulted in documented fatalities, with Cook County recording its 13th heat-related death of the year in August.

## Timeline

### 2026-09-03: Chicago faces dangerous heat wave with high heat indices

Chicago is facing a dangerous late-season heat wave with heat index values expected to exceed 100 degrees, prompting official advisories and warnings regarding heat-related health risks.

4 sources. https://clstr.news/cluster/chicago-faces-dangerous-heat-wave-with-high-heat-indices

### 2026-08-26: Chicago weather forecast for Wednesday, August 26

Chicago weather for Wednesday, August 26, features a high of 84°F (29°C) and a 62% chance of precipitation during the first half of the day.

2 sources. https://clstr.news/cluster/chicago-weather-forecast-for-wednesday-august-26

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Cite as: Chicago extreme heat wave. CLSTR, https://clstr.news/situations/chicago-extreme-heat-wave