Air temperature measurement network

The map shows the location of the air temperature measurement stations. Fragmentary meteorological reports were prepared and published by European explorers in the North American Arctic during the late 16th and 17th centuries. Many employees of the Hudson's Bay Company kept careful observations of weather in Western Canada in the 18th and 19th centuries, and their records are still kept in the archives of the Hudson's Bay Company. Regular detailed weather observations were made for Quebec City, between April 1, 1765 and April 30, 1766. Long-term weather observations in Canada involved daily readings of a thermometer and barometer for the years 1768 and 1769 at Fort Prince of Wales on Hudson Bay. During the years 1788 to 1822, forts and fur trading post were built across the western plains where thermometers, wind vanes, and barometers have been set up. The first official meteorological observations were taken at Toronto Magnetic Observatory on Christmas Day, 1839, and continuous daily temperature readings have been made at Toronto since that time. For a station to be part of the National Climatological Network, the data observed must be derived from official instruments, and their exposure and the observing practices must conform to prescribed standards. The data are processed and included in standard data publications.