More than 500 flights were delayed or canceled at Denver International Airport on Monday as a polar vortex continued to freeze Colorado. There were 529 delayed and 28 canceled flights as of 4:15 p.m., according to FlightAware.  There were 152 delayed and give canceled United Airlines flights and 149 delayed and six canceled Southwest Airlines flights. SkyWest, a carrier for United Airlines, reported 149 delays and 13 canceled flights. Flights headed to Las Vegas and New Jersey also saw delays for weather and staffing, with Las Vegas flights delayed by an average of 46 minutes and New Jersey flights delayed by at least an hour, according to the Federal Aviation Administration. Related Articles Transportation | More than 250 flights delayed, another handful canceled at DIA as freezing weather continues in Denver Transportation | 204 flights delayed, none canceled Saturday morning as snow hits Denver Transportation | Denver forecast to see more than 100 straight hours of below-freezing temps Transportation | Denver International Airport ranks sixth in U.S. for guns found in carry-on luggage Transportation | Denver announces deal to acquire Park Hill Golf Course in a land swap — and make it city’s newest park Metro Denver weather will stay in the single digits or below zero on Monday before warming up to a balmy 40 degrees Tuesday, according to the National Weather Service. Get more Colorado news by signing up for our Mile High Roundup email newsletter.