In a totally non-scientific ranking, Manitoba topped the list of provinces with the worst winters in Canada. X92.9, a radio station in Calgary, was inspired to create the ranking from a Thrillist article that did the same for all 50 U.S. states.
Their ranking of Canada's provinces from best to worst winters were as follows: 8) British Columbia, 7) Ontario, 6) Quebec, 5) Atlantic Provinces 4) Alberta, 3) The Territories, 2) Saskatchewan, and 1) Manitoba.
Google seems to agree with their #1 pick, linking people to a scientific report claiming Winnipeg as the coldest Canadian city:
According to the CurrentResults.com, Winnipeg, Manitoba ranks first when it comes to having the lowest average seasonal temperatures. They also mention how it is the one Canadian city that drops to -30 degrees C most often and is the least likely to have a day above freezing during the winter.
Following Winnipeg in the ranking of Canadian cities with the coldest winter climates are: 2) Saguenay, Quebec, 3) Regina, Saskatchewan, 4) Saskatoon, Saskatchewan, 5) Thunder Bay, Ontario, 6) Sudbury, Ontario, 7) Quebec City, Quebec, 8) Trois Rivieres, Quebec, and 9) Edmonton, Alberta.