Southwest Airlines canceled all of their flights out of Chicago's Midway Airport on Sunday after running low on de-icing fluid for their planes, stranding thousands of passengers.

All 220 flights were canceled as crews continue to clean up from a heavy snowfall in the area.

'We have paused our service for the remainder of the day for the safety of our customers and crews,' the airline said in a statement.

'We will continue to work with our customers on their travel plans and apologize for any inconvenience the disruption in service has caused.'

Southwest Airlines canceled all 220 of their flights out of Chicago's Midway Airport on Sunday after running low on de-icing fluid for their planes, leaving several passengers stranded (Pictured, stranded passengers endure a wait for checked baggage at Chicago Midway)

Southwest has 'multiple glycol deliveries' scheduled for Monday and expects to resume 'close to normal operations' at Midway,

Flights departing and arriving from Chicago's O'Hare Airport didn't fare much better. By late Sunday, a total of 235 flights on all airlines were canceled and the average delay on departing flights was around 22 minutes as of 4pm on Sunday.

At Midway Airport, average flight delays of more than 15 minutes were reported on Sunday afternoon and a total of 264 flights on all airlines were canceled.

Alyssa Eliasen, a spokesperson for the airline, said Southwest had 'actively worked to manage our glycol levels (used to deice aircraft),' but that due to the severity of the winter weather it was forced to cancel the flights.

Southwest has 'multiple glycol deliveries' scheduled for Monday and expects to resume 'close to normal operations' at Midway, she said.

This is not the first time that Southwest has suspended flights because of de-icing problems.

Three days after Christmas, nearly 90 Southwest flights were canceled at Midway Airport because of delays caused by the de-icing of planes (Pictured, a Southwest plane is de-iced at Chicago Midway in January 2014)

Three days after Christmas, nearly 90 Southwest flights were canceled at Midway Airport because of delays caused by the de-icing of planes, according to a statement from the airline.

The airline blamed freezing conditions at the airport for slowing down crews in charge of de-icing the planes, the statement said.

Temperatures in Chicago on Sunday were in the mid-20s, according to the National Weather Service.

Several waves of snow fell on Chicago, including a storm on Friday that dumped as much as a foot of snow in western areas.

Chicago Public Schools canceled classes as a result and more than 1300 flights were canceled at the area's airports.

Even more snow, and some sleet, fell on Saturday night and into Sunday morning, prompting a Winter Weather Advisory and hazardous travel conditions in some areas.