Omicron has airlines across the country short staffed and left thousands of flight passengers scrambling to figure out holiday travel plans.

Thousands of flights were canceled or delayed again nationwide Sunday. It appears that many of the cancellations affecting flights across the country are directly related to Covid. Weather has played a part as well.

Chicago airports were among the airports impacted. O’Hare reported 52 cancellations and Midway reported two.

United Airlines has reported 8 cancellations at O’Hare thus far on Monday morning.

The line for Covid testing for international travelers departing from O’Hare moved slowly Sunday. Passengers reported long wait times for results.

Delta, United and JetBlue have blamed the omicron variant of the coronavirus for staffing shortages that forced cancellations.

JetBlue scrapped 10% of its flights Sunday. Delta canceled 5% and United canceled 4%, according to FlightAware. The three airlines canceled more than 10% of their scheduled flights on Saturday.

American Airlines spokesperson Derek Walls said the Christmas cancellations stemmed from virus-related sick calls.

Nationwide, more than 50 flights were already canceled for Monday.