(CNN)-- A senior White House official said Sunday that President Donald Trump is expected to deliver his scheduled speech for American Independence Day, but the time may change due to weather conditions.

The speech was scheduled for approximately 9:45 p.m. Eastern Time.

Several US cities recorded new temperature records, coinciding with the 250th Independence Day celebrations.

Atlantic City, New Jersey, tied its all-time high temperature at 41 degrees Celsius, with the previous record set on June 28, 1969.

The National Weather Service will review and verify the record.

Other cities also broke their temperature records on July 4, including Washington, DC, which recorded 39 degrees Celsius.

The previous record was 38 degrees Celsius, set in 1919.

Norfolk, Virginia, recorded 38 degrees Celsius, with the previous record of 37 degrees Celsius set in 1879.

Independence Day celebrations are being held across the United States to mark the 250th anniversary of the founding.

An intense heat wave forced organizers to modify or cancel events in the capital and in communities along the East Coast.

Now a severe thunderstorm threat looms, with increasing likelihood of storms in the Washington, DC area Sunday evening.