Mapped: 19,000 US flights canceled due to the huge winter storm — marking the worst weekend for air travel since COVID

• Over 19,000 flights within, into, or out of US airports have been canceled since Saturday, per FlightAware.
• Sunday was the worst day for cancellations since the early days of the pandemic.
• Business Insider created a map to show the 20 worst-affected airports.

Thousands of flights were canceled this weekend as Winter Storm Fern brought heavy snow and ice to much of the country.

19,450 flights within, into, or out of US airports were canceled between Saturday and 7 a.m. ET on Monday, according to data from FlightAware.

The majority of those, more than 11,000, occurred on Sunday. That made it the worst day for flight cancellations since the early days of the COVID-19 pandemic.

Disruption continued on Monday, with 3,700 flights canceled as of 7 a.m. ET, per FlightAware. At that time, Boston Logan Airport appeared to be the worst affected, with 60% of its departing flights canceled. However, the situation overall was improving.

Dallas-Fort Worth International Airport was the worst affected this weekend, with around three-quarters of its scheduled flights canceled. By Monday morning, 3,200 flights in and out of the airport had been canceled.

Four inches of snow fell in 48 hours at the airport, which is American Airlines' main hub, per the National Weather Service.

The second-most cancellations were seen at Charlotte Douglas, another American Airlines hub, numbering almost 2,000 between Saturday and Monday.

DFW had nearly twice as many cancellations as Atlanta's Hartsfield-Jackson International, Delta Air Lines' primary hub, which ranked third.

The New York City area's three airports — JFK, LaGuardia, and Newark — each saw about 1,500 cancellations. Close to 10 inches of snowfall was recorded at each location, the local CBS News outlet reported.

Using FlightAware's data, Business Insider created this map that shows the number of cancellations at the 20 worst-affected airports.

American Airlines was the worst-affected carrier on Sunday with nearly 1,900 cancellations, representing 58% of its schedule, per FlightAware's data.

The airline said it added 3,200 extra seats on flights in and out of Dallas-Fort Worth, and another 3,000 on flights from Charlotte to Chicago O'Hare.

On Thursday, it said it was "repositioning aircraft, aligning crew resources, and reinforcing staffing at key airports" to help minimize disruption.

Airlines waived change fees for passengers flying to or from cities affected by the weather.

Delta Air Lines, which canceled nearly 1,500 flights, per FlightAware, said it was operating a reduced schedule as freezing rain and ice hit Atlanta.

It also said it was bringing in additional reserve pilots and flight attendants, plus "relocating experts from cold weather hubs" to several airports in the South, to support its de-icing and baggage teams.