More than 125 million Americans under dangerous heat coast to coast

Key Points:

• Over 125 million Americans face extreme heat alerts from Southern California to the Northeast, with daily record highs expected in cities like Rapid City, Fargo, and Syracuse.
• Dangerous heat indices near or above 100 are forecasted across the upper Midwest and Northeast, including Philadelphia, Washington, D.C., and New York City, where heat waves could last through Saturday.
• Smoke from over 800 Canadian wildfires will degrade air quality in the upper Midwest and Northeast starting Wednesday, compounding health risks amid the heat.
• Southern California is under heat advisories through Thursday, with interior valleys reaching temperatures up to 110 degrees, while Northern California cities like San Jose will see highs in the mid to upper 90s.
• South-Central Texas faces a significant flood threat with potential rainfall exceeding 15 inches over three days, and northern New England is at risk for severe storms with damaging winds, large hail, and possible tornadoes on Tuesday afternoon and evening.