Dozens of flights headed to and from Denver International Airport have either been canceled or delayed Monday.

As of 6 p.m. 152 flights were delayed and 23 had been canceled, according to FlightAware.

United Airlines had the most canceled flights with 12. Air Canada, Allegiant Air, American Airlines and Southwest were other airlines with more than one flight canceled. 

Across the United States more than 2,700 flights were canceled and an additional 237 flights were delayed, according to FlightAware. 

Traveling in the skies was expected to increase over the holiday weekend as DIA officials were anticipating travel numbers that would near or exceed pre-pandemic numbers.

The airport predicted that nearly 1.2 million passengers would pass through the airport throughout the holiday weekend.

Additionally, AAA predicted that 47.9 million Americans — the second-highest travel volume on record — would hit the roads and skies this weekend. 

Airport officials are urging passenger to check with their airline for their flight status before heading to the airport and arrive at least two hours ahead of time due to security lines.