As many as 746,000 homes in the United States on Saturday are without electricity – including air conditioning – as a heatwave withers much of the country's Midwest, East Coast and South.

The outage number is from the website PowerOutage.com, which also cites extreme weather, which would include lightning storms, for lost power. 

Temperatures in New York City are forecast to reach 101 degrees and 104 in Washington, D.C., central to the country's July 4 and 250 birthday celebrations. 

The country's mid-Atlantic region has been under triple-digit temperatures for three consecutive days now, with forecasted storms Saturday night not expected to significantly lower temperatures until at least Monday, when 80-degree temperatures are expected. 

In Philadelphia, the Salute to Independence Semiquincentennial Parade set for Friday was canceled due to the dangerous heat wave, according to ABC News. And the 250th anniversary celebration on the National Mall in Washington, D.C., was suspended Saturday for a few hours because of the extreme heat.