Millions of Americans heading out for Fourth of July celebrations may have to contend with a mix of dangerous heat, severe thunderstorms and flash flood threats as weather conditions vary dramatically across the United States this holiday weekend.
Forecasters have warned the most intense heat will grip the eastern half of the United States, with some locations expected to experience temperatures 10 to 20 degrees Fahrenheit above average. Combined with high humidity, conditions could feel as hot as 115 degrees in some areas.
