Airport security
Thousands of flights were delayed or cancelled in the US as nearly a dozen states brace themselves for a winter storm.Spencer Platt/Getty Images

Severe weather throughout the US has led to hundreds of flights being delayed and cancelled following the Christmas holidays. Airports in the Midwest, in particular Chicago O'Hare International Airport, have experienced the worst delays and cancelations.

According to FlightAware.com, all inbound flights were being held at their origins until 5pm CST/11pm GMT, with an average delay of 7 hours and 33 minutes for inbound flights at O'Hare. The airport also experienced departure delays on average of 40 minutes. ABC News reported that over 1,000 flight cancellations involved Chicago airports. More than 400 of those cancellations involved airports in Texas.

By 6pm EST/11pm GMT, over 2,300 flights had been cancelled within, in or out of the US on 28 December. The cancellations mark a steep rise from cancellations nationally on 28 December in 2014, when there were 200 cancellations, and from 28 December 2013, when there were 151 cancellations.

Delays from within, in or out of the US on 28 December of this year have already reached 3,865, the flight tracking website reported. The largest number of flight delays come from Dallas Fort Worth International Airport with 268 flight delays. Chicago O'Hare follows closely behind with 203 delays. The two airports, along with Chicago Midway International, lead with the largest number of flight cancellations.

According to The Associated Press, parts of 11 states in central US are under a winter storm warning as the severe storm system that brought deadly tornadoes to Texas and flooding to Missouri and surrounding states. Iowa, Wisconsin, Michigan along with parts of Minnesota, Illinois, Missouri, South Dakota, Nebraska, Kansas, Oklahoma and Texas are expected to see winter weather, including heavy snow and ice.