Because cabins and camps were ill-suited to a Canadian winter, the number and variety of motels grew dramatically after World War II, peaking just before freeways such as Ontario Highway 401 opened in the 1960s. Due to Canada's climate and short tourist season, which begins at Victoria Day and continued until Labour Day or Thanksgiving, any outdoor swimming pool would be usable for little more than two months of the year and independent motels would operate at a loss or close during the off-season.