Heatwave threatens Independence Day events across the U.S. East Coast
A heat dome is driving temperatures and humidity to record levels in the Northeast and Mid-Atlantic, prompting warnings from officials and limiting public gatherings for July 4 celebrations.
Temperatures across the U.S. East Coast are expected to reach 38 °C (100 °F) with heat-index values as high as 115 °F in cities such as Washington, D.C., Philadelphia and New York over the July 4 weekend, according to the National Weather Service. The agency warned that the prolonged heat, with little overnight relief, poses risks for anyone without adequate cooling or hydration.
New York City Mayor Zohran Mamdani urged residents to stay indoors and keep cool, noting that the city could see its first 100 °F day in Central Park in 12 years. Washington, D.C., may experience four consecutive days of 100 °F temperatures, a rarity that has occurred only twice before.
In Washington, Capitol Police limited attendance at a rehearsal for a July 4 concert to essential personnel because of concerns about large crowds in the extreme heat. President Donald Trump has said he plans to deliver a speech outdoors despite forecasts of temperatures near 107 °F.
The heat dome, a persistent high-pressure system, is reinforced by dry soils and drought conditions in the Northeast, which amplify warming. Climate scientists attribute the increasing frequency and intensity of such heatwaves to human-induced climate change.
Temperatures are expected to dip slightly on July 4 as thunderstorms move in, but will remain well above normal through the following weekend before cooler air arrives from the north.