A heat dome threatens the Fourth of July weekend with extreme temps and power strain

Temperatures are set to rise as a heat dome forms over parts of the US. Spencer Platt/Getty Images A heat dome is sending temperatures soaring in parts of the central and eastern US. The extreme temperatures come just around the corner from the Fourth of July holiday weekend. High electricity use is straining the grid, and Chicago residents are being told to reduce consumption. An intense heat dome is building across parts of the US ahead of the Fourth of July holiday weekend. People in central and eastern US are experiencing extreme temperatures and high humidity because of the heat dome, with New York City expected to experience its sixth-hottest weather since 2000, according to a Tuesday report from AccuWeather. A heat dome occurs when the atmosphere traps hot air, like a lid over an area, preventing it from dispersing or forming clouds. Temperatures of above 100 degrees are forecast for millions of people. NYC Mayor Zohran Mamdani expanded measures to protect New Yorkers from the extreme heat , announcing extended hours for public swimming pools and cooling centers for vulnerable residents. "It could get hit 100 degrees, with temperatures feeling as hot as 112 and staying hot into the weekend," Mamdani said in an Instagram post on Tuesday. He said this could affect people celebrating the World Cup, the Fourth of July, or "renting out MSG to get married, hypothetically," alluding to Taylor Swift and Travis Kelce's rumored wedding in NYC's Madison Square Garden on Friday. The heat dome comes right before the Fourth of July weekend, which marks the US's 250th anniversary, when AAA predicted 72.2 million Americans would travel. Special heat measures are being taken during the Fourth of July fireworks event at the National Mall in Washington, DC. "In light of current heat conditions, Freedom 250, United States Park Police, National Park Service, the United States Secret Service, and the Federal Emergency Management Agency have coordinated closely to adjust event timi