More than 2,700 flights have been canceled at US airports.
On Saturday, air traffic in the United States was seriously hampered, with inclement weather in several sections of the country compounding the impact of a massive rise in Covid-19 infections fueled by the Omicron variety.
Around 11:00 p.m. (0400 GMT Sunday), the United States had 2,723 cancelled flights, accounting for more than half of the 4,698 worldwide, according to flight tracking website FlightAware.
Furthermore, 5,993 domestic flights were canceled on Saturday, out of a total of 11.043 worldwide.
According to the site, the worst-affected US airline was SkyWest, which had to cancel 23 percent of its flight schedule.
In the United States, Chicago airports were particularly heavily struck by inclement weather.