2 horses ran onto a Los Angeles freeway and were hit and killed by passing vehicles

This Fourth of July, it’s not just the hamburgers that are sizzling: millions of people are under heat warnings as many Americans have traveled to celebrate the birth of their nation with parades, barbecues and fiery splashes of color in the evening sky.

Travel numbers are expected to drop as people already clog airports and highways to get to their destinations ahead of the Fourth of July. Meanwhile, in the Western U.S., residents battled oppressive heat as the National Weather Service warned of a “significant and extremely dangerous” heat wave across much of the region, the AP reported.

The number of fireworks displays – a staple of the holiday – was expected to reach new highs, with countless backyard displays and 16,000 professional shows lighting up the horizon from coast to coast.

“This is how we celebrate. It’s the bombs exploding in the air. It’s the red glow of the rockets. This is how people show their pride and patriotism,” said Julie Heckman of the American Pyrotechnics Association.

All signs pointed to major celebrations: The Transportation Security Administration reported that nearly 3 million people traveled through airports in a single day last week — a record, and that number is expected to be surpassed this week. And AAA predicted that 60.6 million people will travel by car during the holidays. Part of the boost was attributed to easing inflation, although many Americans remain concerned about the economy.

In much of the west coast, residents were advised to take precautions to avoid overheating over the holidays.

Temperatures were expected to exceed 100 degrees Fahrenheit (38 degrees Celsius) in coastal and inland areas of California, with heat extending into the Pacific Northwest. Temperatures were expected to exceed 120 degrees Fahrenheit (49 degrees Celsius) in some desert areas of the Southwest. Hot, muggy conditions also prevailed in the Deep South and Mid-Atlantic.

The annual fireworks display in the Northern California city of Oroville was canceled as the growing Thompson Fire left some 26,000 residents homeless while hundreds of firefighters battled extreme heat to prevent the flames from spreading to more homes.

From Maine to Hawaii, there was plenty of barbecue, desserts, cold drinks, and the Stars and Stripes. But Americans also celebrated in other ways that were unique to their communities.

Off the rocky coast in Down East, Maine, some wanted to take part in lobster boat races. Descendants of the signers of the Declaration of Independence rang the Liberty Bell 13 times in Philadelphia – once for each of the original colonies. The Californian communities of Bolinas and Stinson Beach, north of San Francisco, held their annual tug-of-war contest, in which the losers end up in a lagoon.

And of course there is the annual hot dog eating contest at Coney Island in New York.

The Fourth of July holiday generally unites Americans in their shared love of their country, but the 2024 edition takes place against a backdrop of deep political polarization and a divisive presidential campaign.

In Boston, where tens of thousands were expected to attend the Boston Pops Fireworks Spectacular, Maestro Keith Lockhart said it was inspiring to see people of different political persuasions coming together on the Charles River Esplanade, but noted that “you’d have to have your head pretty deep in the sand not to see the deep divisions in our country.”

“These are indeed dangerous times,” he wrote in an email before the show. “If we can put aside our differences and embrace our commonalities, even for one day, that must be a positive thing.”