Southwest canceled hundreds of flights over Christmas weekend

• Southwest Airlines canceled more than 400 flights across the Christmas weekend due to dense fog.
• The airline's operation is "stable and healthy" as of Tuesday, with only a few cancelations.

Southwest Airlines canceled hundreds of flights since Sunday due to dense fog at Chicago Midway International Airport, but the airline's operation is "stable" going into the post-holiday.

According to data from the aircraft-tracking website FlightAware, Southwest has only canceled two flights and delayed another 700 as of 11:45 a.m. EST on Tuesday.

"Our operation is currently healthy and stable and we do not anticipate any significant disruptions for Tuesday," Southwest told Business Insider. "We continue to have all hands on deck as our employees work to safely take care of our customers during this busy holiday travel season."

Today's recovery compares to the more than 400 flights canceled on Christmas Eve and Christmas Day. Southwest told BI that number is out of the "approximately 4,300" systemwide flights scheduled across those two days.

The chaos at Midway — Southwest's fourth-busiest operation, where it owns about 90% market share — caused many customers to worry about a repeat of the airline's infamous 2022 holiday meltdown.

Last year's Christmas chaos, which resulted in some 17,000 flight cancelations, started with a brutal winter storm but snowballed due to Southwest's antiquated crew scheduling software which couldn't keep up with the disruptions.

The airline has paid millions for the operational breakdown, including a recent $140 million civil penalty from the Department of Transportation for "violations of consumer protection laws."

The DoT said the penalty is the largest it has imposed for violating consumer protection laws and that the money "will mostly go toward compensating future Southwest passengers affected by cancellations or significant delays caused by the airline."

The payment is on top of the $600 million Southwest has already paid out in refunds and reimbursements to impacted customers.

"It was an ugly week," Southwest CEO Bob Jordan told Bloomberg in mid-December, speaking on how the company planned to avoid the same chaos this year. "But that week does not define Southwest Airlines."