Torontonians and other parts of the GTA and beyond woke up to some heavy dense fog Sunday morning.
Fog so heavy Environment Canada issued a fog advisory for Toronto, Hamilton, as well as the regions of York, Durham, Halton, and Peel.
That advisory had ended.
At times there was zero visibility throughout the city and more specifically on the roads. Many parts of the 400 series highways as well as the Don Valley Parkway were blanketed with dense fog that made driving difficult.
So why the heavy fog in December? Environment Canada's Ria Olsen chalks it up to the above seasonal warmer temperatures.
"That's part of it, we have a warmer air mass that's come over us and it's a bit more moist as well."
But Olsen warns by week's end, it will be a totally different outlook and feel for temperatures as we head back to more seasonal values below the freezing mark.
"The cold front will track across Southern Ontario on Tuesday and you'll really notice a difference Wednesday morning once the cold air has rushed in. Looks like this cold air will hang around for quite a while."