More than 60 million people were under heat alerts across the country Wednesday, from Phoenix to St. Louis and from Detroit to New York City.
High temperatures were forecast to soar 10-15 degrees Fahrenheit above average across the East on Wednesday, meaning that in cities including Washington D.C. and Philadelphia, temperatures in the upper 80s to low 90s could feel closer to 100 degrees when combined with high humidity.
Away from the urban corridor, some interior locations such as Syracuse and Binghamton, New York, also are feeling the heat. Erie, Pennsylvania, and Islip, New York, could set new record highs.
Across the Midwest and the Plains, temperatures are forecast to feel even hotter. Through Friday, St. Louis is forecast to feel close to 110 degrees. In Oklahoma City, the heat index is forecast to reach 103 degrees on Wednesday and 102 on Thursday.
The desert Southwest will be hottest of all, with high temperatures climbing into the 110-115 degree range for cities such as Phoenix and Tucson, Arizona.
The heat and humidity will break this weekend in the Northeast, but will continue in other areas from the Midwest to the mid-Atlantic.
Hotter temperatures are lasting later into the year as climate change continues to warm the atmosphere. For those over the heat, the first day of astronomical fall is less than a month away, on Sept. 22.