A dangerous heat wave blanketing much of the East Coast disrupted Fourth of July celebrations in Washington, D.C., forcing organizers to cancel or delay several events planned for the nation’s 250th Independence Day.

A heat dome settled over much of the eastern United States through the holiday weekend, sending temperatures into the triple digits. Washington remained under an “Extreme Heat Warning” on Saturday, with the National Weather Service forecasting a heat index as high as 113 degrees.