The National Capital Region saw about 15 millimetres of freezing rain on Sunday after 18 centimetres of snow fell late Saturday, and everything is expected to freeze with cold temperatures returning.

Ottawa residents were forced to navigate slippery roads and sidewalks on Sunday after freezing rain and rain followed about 18 centimetres of snow. (Michel Aspirot/CBC) Roads and sidewalks remained very slippery and those who don't have to travel were advised to avoid it by Environment Canada.

Freezing rain delayed many flights at the Macdonald-Cartier International Airport in Ottawa and forced the closure of the Camp Fortune ski resort.

Environment Canada also issued a special weather statement warning of the coldest temperatures of this winter beginning late Sunday night due to a "frigid Arctic airmass."

"Extreme cold warnings will likely be required at times during the week due to the combination of cold temperatures and brisk winds," the statement read.

Ottawa’s expected low overnight Sunday was a brisk minus 16 degrees Celsius with the wind making it feel like minus 25. Ottawa Public Health also issued a frostbite advisory for Monday when there will likely be a flash freeze.