Over 56 million Americans are being urged to be cautious on Monday as high temperatures and extreme heat builds in the Central U.S.
Millions of residents along the Mississippi River, from the Twin Cities to northeast Missouri, are under an excessive heat warning. The high temperature in Minneapolis is expected to reach the low 90s on Monday, but due to high humidity, the head index could top 105.
The heat index could top 110 in northeast Missouri, the National Weather Service warned.
RELATED STORY | Hurricane Hone sweeps past Hawaii, dumping enough rain to ease wildfire fears
An excessive heat warning is also in place for Chicago. The high temperature on Monday is expected to soar in the mid 90s with the heat index exceeding 110.
The National Weather Service said when heat indices top 103, heat cramps or heat exhaustion is likely and heat stroke is possible with prolonged exposure and/or physical activity.
After Tuesday, the extreme heat will be replaced by more normal summer temperatures in Chicago and Minneapolis. The shift in temperatures could cause a threat of severe weather in the Midwest over the next few days, however.
Due to extreme heat, some school districts in the Midwest are closed on Monday. Among them, over a dozen schools in the Milwaukee area announced they will close on Monday.
RELATED STORY | California's Park Fire is 25% contained, now the 4th largest in state history