About 380,000 customers across Michigan had no power on Tuesday night, after a day of thunderstorms and extreme heat in the Midwest.

The outages affected customers in more than two dozen counties in the state, according to the tracking site poweroutage.us. More than 200,000 of those customers get their electricity from DTE Energy, which is based in Detroit. The company attributed the outages to strong storms, saying it had brought in 800 extra workers to help fix the grid.

More than eight million people in Michigan, Illinois and Indiana were under a severe thunderstorm watch as storms moved through the region on Tuesday night, according to the National Weather Service. The advisory covered Chicago.

On Tuesday morning, the Minnesota State Fair delayed opening for two hours to assess damage from heavy wind and rain.

The region has also been grappling with an intense heat wave that was expected to continue for a few more days. The Weather Service said in an advisory on Tuesday that high temperatures were forecast to be 10 to 15 degrees Fahrenheit above average in parts of the Midwest, the Southeast and the Mid-Atlantic.

Several Michigan school districts closed schools early on Tuesday because of extreme heat.