A flash flood warning was issued for the Castle Rock area in Douglas County on Wednesday, July 29, 2026, amid heavy rains and a thunderstorm stretching to Denver International Airport. The storm produced hundreds of lightning strikes during the mid-afternoon hours, intensifying flood concerns across the region.
In response, the Federal Aviation Administration (FAA) implemented a ground stop at Denver International Airport. This ground stop, scheduled to remain in effect until 5 p.m. local time, temporarily suspended all flight departures and caused delays for travelers at the airport.
Heavy rainfall contributed to traffic congestion on Interstate 25 south of Denver.
Due to the elevated flood risk, local authorities designated July 29, 2026, as a First Alert Weather Day for the affected areas, primarily Douglas County and Castle Rock.
