A new heat dome is forming across the United States, locking in sweltering conditions from the Gulf Coast to the Midwest and potentially pushing temperatures to yearly highs in major cities like Chicago, St. Louis, and Memphis, CNN reports.
While this heat wave may not break records like the one on June 24, officials warn it could still be extremely dangerous, with heat indexes well into the triple digits and a Level 3 of 4 heat risk stretching as far north as Michigan. The stifling heat is expected to build from July 22 and peak around July 23–24, bringing life-threatening conditions to millions. Humidity will worsen the impact, particularly in areas unused to prolonged high heat.
The globe is warming up, with summers getting hotter every year. According to the World Meteorological Organization, climate change is driving these rising temperatures in various parts of the world, with serious consequences. Wildfires destroy homes and take lives, extreme heat threatens the food supply, and the elderly are especially at risk. And in Europe and Central Asia, half of all children face frequent heat waves—twice the global average of one in four children.
To find out more about the biggest heat waves ever, read up on the hottest days in history in this gallery.