Long-term and high-quality weather stations were selected in each province and territory and weighted by the area they represent in terms of the geography. For example, in British Columbia data for 22 weather stations were weighted by their representative area in order to calculate a BC-wide value for each weather category.The 70 Weather Categories
Among the weather elements analyzed in this study were: temperature, rain and snow, bright sunshine, atmospheric pressure, visibility, sky conditions, wind speed, humidity and the state of the weather (e.g., thunderstorms, blowing snow, fog, smoke and haze). From these basic elements, 70 weather categories were developed by season and by year (for example, the province-territory with the sunniest winter or the foggiest year-round).
Determining which province or territory is the weather winner depends on how the category is defined. For example, which province can lay claim to being the sunniest in Canada? Is that the sunniest day, month, summer or year on average? For this study, the sunniest province-territory was defined as the jurisdiction with the greatest number of hours with bright sunshine year-round. Since this weather element generates a great deal of interest, eleven categories were selected for "the sunniest", including seasonal information (such as "the sunniest winter") and tallies for the number of hours and days with sunshine. Many of the definitions, such as hot days (30° C or higher), or cold days (-20°C or lower) are standard meteorological concepts.The Timeframe – 30 years
The basic data used in this study was the climate "normal." A normal is an average of a weather element (such as temperature or rainfall) for a specific location over a relatively long period of time. The time frame is usually three consecutive 10-year periods. In keeping with international standards, countries re-compute their normals every decade to keep up with any changes in climate. In 2003, Environment Canada's Meteorological Service of Canada compiled a new set of climate normals covering the period 1971 to 2000. Climate normals and their companion statistics are used as the basic data reference for 10 years.