U.S. heat wave threatens July 4 celebrations, prompts cooling centers

A massive heat dome is covering the central and eastern United States, driving temperatures to 100‑115 °F (38‑46 °C) and heat‑index values above 100 °F. The National Weather Service reports that more than 60 million people are under heat alerts as the wave moves from the Midwest toward the East Coast through the Independence Day weekend.

Major cities are opening cooling centers and deploying emergency measures. New York City, Chicago, Detroit, Baltimore, Washington, and Montgomery County have activated hundreds of air‑conditioned locations, while Maryland’s governor declared a State of Preparedness to coordinate resources. Localities in Alabama, Westchester, New Jersey, Maryland, and even rural Wisconsin counties are urging residents to stay hydrated, limit outdoor activity, and check on vulnerable neighbors.

Health officials warn of heat‑related illness, dehydration, and heat stroke, especially for the elderly, children, pets and people on certain medications. The heat is also affecting the 2026 World Cup matches scheduled during the holiday and has already delayed sporting events. Isolated severe‑storm chances have been added for parts of the Midwest later in the week, but the primary threat remains the prolonged extreme heat.

Residents are advised to use cooling centers, seek shade, drink water, avoid alcohol and caffeine, and never leave people or animals in parked cars.