Denver International Airport is going to be very busy during Labor Day weekend.

The airport is expecting another record holiday weekend with nearly half-a-million passengers going through security between Thursday and Tuesday, according to DIA.

Denver’s busiest days will be Friday and Monday, the airport said, with more than 177,000 passengers forecasted each day.

The airport has been breaking passenger records all year. Each month this year, the airport set new highs. For the Fourth of July weekend, DIA saw nearly a million travelers coming through.

This Labor Day weekend is expected to see traffic up 5% compared to last year, according to the airport.

DIA warns security lines will likely take longer over the weekend and travelers should show up at least two hours early to give themselves extra time.

Travelers can also make a reservation to skip the security line through the new west checkpoint at www.flydenver.com/security/den-reserve/.

United Airlines flight attendants union kicks off process to strike

United Airlines, Denver’s largest operating air carrier, also expects its busiest Labor Day weekend yet as the union representing its flight attendants became the latest to vote for a strike authorization.

On Wednesday, the airline’s flight attendant union announced 99% of its members voted to authorize a strike to negotiate “double-digit” pay increases, pay for work time done on the ground, more scheduling flexibility, retirement and more.

The union has been working on a deal with United for nearly three years.

A strike authorization is the first step unions take toward striking if contract negotiations are stalling — but it’s a lengthy process due to strict federal regulations around airline worker unions.

United’s flight attendants can’t legally strike over the busy holiday weekend due to the process, but union leaders said the vote’s timing shows the airline what impacts could look like if negotiations don’t improve.

“We deserve an industry-leading contract. Our strike vote shows we’re ready to do whatever it takes to reach the contract we deserve,” said Ken Diaz, president of the United chapter for the Association of Flight Attendants, in a news release. “We are the face of United Airlines and planes don’t take off without us. As Labor Day travel begins, United management is reminded what’s at stake if we don’t get this done.”

The airline has more than 450 flights scheduled to depart Denver everyday over the weekend and expects about 45,000 passengers going out of its hub. United’s most popular destinations out of Denver are Boston, San Diego, New York, Seattle and Orlando.

In a statement, a United spokesperson said there are no expected flight disruptions from the strike authorization this weekend due to the lengthy federal process.

“We continue to work toward an industry-leading agreement for our flight attendants, including negotiations this week and every month through November,” the statement said. “Both sides have been actively engaged in these negotiations facilitated by the federal mediator requested by the union. We remain eager to reach an agreement.”

It’s the union’s first strike authorization since 2005, when United was wrapping up its bankruptcy proceedings.

United’s flight attendant union also noted voting for strike authorization helped push negotiations for American, Alaska and Southwest workers, all which never reached a strike.

With the vote, the union can request permission to strike from the National Mediation Board, setting a 30-day “cooling” period and a strike deadline.

The American Airlines flight attendant union asked the board for permission to start the 30-day countdown for a strike but was rejected after the panel decided the airline and union could still negotiate.

The two parties reached a deal in July after the Biden administration stepped in to avert a strike and a crisis for the airlines industry.

The Associated Press contributed to this report.