"From the normally chilly Russian Arctic to the traditionally sweltering American South, big swaths of the Northern Hemisphere continued to sizzle with extreme heat as the start of summer more resembled the dog days of August.
In the United States a heat dome of triple digit temperatures in many places combined with high humidity oscillated from west to east. On Thursday, at least eight states hit 100 degrees (37.8 degrees Celsius) and at least nine high temperature marks were set or broken, according to the National Weather Service, which held 30 million Americans under some kind of heat advisory.
The extreme discomfort of Thursday came after 12 states broke the 100-degree mark on Wednesday and 21 records were tied or broken. Since June 15, at least 113 automated weather stations have tied or broken hot-temperature records. Scientists say this early baking has all the hallmarks of climate change."
Seth Borenstein reports for the Associated Press June 24, 2022.