CHICAGO — A dangerous heat dome settled over the Midwest and Great Lakes on Tuesday, prompting extreme heat warnings for major cities including Chicago, Detroit, St. Louis, Nashville, Cincinnati, Kansas City and Des Moines, the National Weather Service said.
Temperatures in Chicago, Minneapolis, Milwaukee, Detroit and St. Louis climbed into the low to mid-90s degrees Fahrenheit (mid-30s Celsius) on Monday and Tuesday, with humidity pushing the heat index to between 105 and 110 degrees Fahrenheit (41 to 43 degrees Celsius), according to forecast data from the National Oceanic and Atmospheric Administration's Weather Prediction Center. Forecasters said heat index values could reach as high as 115 degrees Fahrenheit (46 degrees Celsius) in some locations, with overnight lows in the 70s offering little relief.
The high-pressure system, known as a heat dome, traps hot air near the surface for days or weeks at a time, the National Weather Service said in a warning issued June 28. The heat is expected to expand eastward into the Mid-Atlantic and Northeast by Wednesday and Thursday, with New York, Philadelphia, Baltimore and Washington, D.C. forecast to see record highs into the 100s by Friday and Saturday, according to CBS News meteorologist Nikki Nolan.
Extreme heat watches were also in effect across much of the Northeast, with the most intense conditions expected to coincide with the July 4 holiday weekend before easing.
In the West, separate dangerous fire weather conditions persisted near the Colorado-Utah border, where three firefighters died and two sustained burn injuries after being overcome by flames from fast-moving wildfires, the National Fire Information Center said.
The National Weather Service urged residents in affected areas to limit outdoor activity, stay hydrated and seek air-conditioned spaces, warning that prolonged exposure can cause heat exhaustion and heat stroke. The extent and duration of the heat dome's eastward expansion remained under review by forecasters as of Tuesday.
