Overview

• Daily high temperature records fell in cities from Minneapolis to New York City, with heat indices reaching up to 115°F in parts of the central US.
• The National Weather Service has placed nearly 150 million people under extreme heat warnings, prompting a heat emergency declaration in Philadelphia and advisories in New York City and Washington D.C.
• Officials report dozens of heat-related illnesses, including multiple treatments at a Chicago baseball game, and are urging the public to seek cooling centers and stay hydrated.
• Canada is also feeling the heat as Environment Canada warns communities in Ontario and Quebec of humidex values up to 46°C until Wednesday.
• Forecasters say the heat dome will weaken by midweek, with relief arriving in the Midwest on Wednesday and spreading to the Northeast by Thursday.