A large heat dome over the United States is driving triple-digit temperatures and high humidity across the Midwest, Mid-Atlantic and Eastern seaboard, with the National Weather Service issuing extensive heat advisories and excessive heat warnings affecting tens of millions. Major cities including Chicago, Washington D.C., Philadelphia and New York are reporting heat index values above 105 to 115 degrees Fahrenheit, leading authorities to open cooling centers and implement public health contingency plans. At the same time, wildfire smoke from unprecedented northern forest fires is degrading air quality, while 19 state attorneys general and major cities sue the EPA over greenhouse gas rollbacks.

Prepared by Olivia Bennett and reviewed by editorial team.