720 flights were cancelled and more than 2,200 delayed across the United States on August 3 due to severe thunderstorms. JetBlue led domestic cancellations with 134 flights grounded, followed by PSA Airlines with 56 and Delta with 52. Delta, American, and United issued travel waivers waiving change fees for affected passengers through August 6. As wel las the 720 flights cancellations, more than 2,200 flights delayed nationwide on Monday, August 3, 2026, according to flight-tracking service FlightAware. Under federal airline notification rules enforced by the Department of Transportation (DOT), carriers are required to notify passengers of known delays and cancellations.