73.8% of domestic flights departed Salt Lake City International on time in December 2022, according to the U.S. Department of Transportation.

Context: That’s down from 86.5% in November 2022, a 12.7 percentage point drop, per recently released data from the department’s Bureau of Transportation Statistics (BTS).

The big picture: Nationally, just 69.1% of December’s flights departed on time.

• That figure sits between 75-80% in a typical month, albeit with predictable dips in the busy — and often meteorologically challenging — summer and winter travel seasons.

Zoom in: Salt Lake’s Airport got 3.1 inches of snow last November, while December saw 22.6 inches pile up, the airport’s director of communications and marketing Nancy Volmer told Axios SLC.

• “This resulted in more de-icing activity and snow removal, which can impact flight operations,” she said, adding extreme winter weather can have a “ripple effect” of delays and cancellations nationwide.

Zoom out: Salt Lake City International Airport typically has a strong reputation for its on-time service, ranking third globally and first in North America for on-time service in 2022, according to a study by aviation analytics firm Cirium.

Driving the news: The real story in December was, of course, Southwest Airlines’ epic meltdown.

• 54.8% of Southwest flights departed SLC on time in December.
• Just 57.3% of Southwest’s December flights departed on time nationally, compared to 77.2% for Delta Air Lines, 72.5% for American Airlines and 70.7% for United Airlines.
• Southwest’s struggles dragged down the average for all carriers reporting data to BTS.

Yes, but: All indications so far suggest Southwest has recovered nicely since December, though BTS’ data reports lag by about three months.

• The airline has promised to update key systems that exacerbated December’s meltdown, as well as better communicate with passengers whose flights are delayed or canceled in the future.

What they’re saying: “We spend a lot of money on technology and recently put in a new state-of-the-art maintenance system, a new reservation system and a new human capital workday system,” Southwest CEO Bob Jordan told Axios’ Eleanor Hawkins.

The bottom line: December was truly just as bad as it seemed, the data shows.