Image of the 250th anniversary fireworks display promoted by 'Freedom 250' [Captured from the Freedom 250 homepage]

As the United States celebrates its 250th anniversary this year, the Independence Day (July 4) event in Washington, D.C., is expected to face significant congestion due to record-breaking heat waves and large-scale crowd control measures.

According to the 'Freedom 250' website, the event organizer, on the 30th (local time), the program is set to include an air show featuring hundreds of fighter jets, military reviews and marching band performances, musical acts, and finally, a speech by President Donald Trump followed by a fireworks display, starting from the afternoon of the 4th, which falls on a Saturday.

The biggest concern is the heat wave sweeping across the U.S. East Coast. Forecasts indicate temperatures early next month that rival the deadly heat waves seen in Europe. Daytime temperatures are expected to soar into the high 30s (°C), with heat indices exceeding 40°C. Washington, where the event will be held, is also included in the heat wave advisory area.

Given the attendance of high-profile figures, including President Trump, organizers have announced that they will restrict vehicle traffic around the National Mall starting at 1 p.m. and implement airport-style security screenings to manage the large crowds and ensure safety.

Washington Police Chief Jeffrey Carroll stated at a press conference that this event will have the highest level of security of any Independence Day celebration since the 9/11 attacks in 2001. According to CBS News, the event has been designated as a "National Special Security Event," similar to the Super Bowl or a presidential inauguration.

U.S. media outlets have pointed out potential safety risks, as large crowds will be spending long hours outdoors with no place to escape the heat. An observation area has been set up around the Washington Monument within the National Mall, with a capacity of 150,000 people.

Many of these attendees are likely to stay in place to watch the fireworks show scheduled for late at night. Organizers announced to the media that the fireworks display would start later than in previous years, at 10:30 p.m. or possibly after 11 p.m.

It is presumed that the fireworks schedule was pushed back because President Trump is slated to deliver his speech during the prime-time slot around 9 p.m. There is criticism that he has designed this event, held ahead of the November midterm elections, essentially as a "political rally" to boost his approval ratings.

Approximately 850,000 fireworks—potentially breaking the Guinness World Record (currently around 810,000)—are scheduled to be launched over the Potomac River for 40 minutes. Pyrotecnico, the fireworks company in charge, told the Washington Post (WP) that they plan to deliver "the best fireworks display you have ever seen or will see."

The problem is that in stagnant atmospheric conditions with little wind, gunpowder smoke from the fireworks will not disperse, which could not only hinder the view but also negatively affect the respiratory health of spectators. A representative from Pyrotecnico stated, "We are hoping for a light breeze."

Washington Mayor Muriel Bowser said at a press conference, "This Saturday will be a very long day," adding, "Families with young children might decide it is better to watch it on TV or at a local neighborhood event."