Major to extreme heat risk forecast across central and eastern U.S. through the July 4 holiday

A strengthening upper-level ridge is forecast to intensify a prolonged and dangerous heat wave across much of the central and eastern United States through at least July 10, 2026, with temperatures in the low to upper 30s°C (90s to lower 100s°F) and heat index values reaching 38–43°C (100–110°F), locally up to 46°C (115°F). Source