A dense fog advisory issued by the National Weather Service caused major travel disruptions across New York City airports Monday, leaving hundreds of flights delayed or canceled - and travelers scrambling to adjust their plans.

The thick fog blanketing the region Monday night reduced visibility both on the ground and in the air, creating difficult flying conditions for pilots across the country.

Passengers inside the terminals say the experience has been frustrating.

“I could punch through a wall right now. I’m just like over it,” said traveler Scarlett Kelch.

Across New York City’s major airports, hundreds of flights have been canceled or delayed in the last 24 hours. At LaGuardia, more than 370 departures were removed from the boards, forcing many travelers to rethink their plans.

Inside the terminals, crowds of travelers continued monitoring departure boards and hoping their flights would still take off.

The National Weather Service says the foggy conditions are expected to last through 1 a.m. Tuesday, with visibility at times dropping to less than a quarter mile.

Travelers heading to the airport overnight are advised to check with their airlines for the latest flight status updates.