Natural Resources Canada

The map shows the mean January daily temperature based on the 30-year period 1941-1970. The lowest mean January daily temperatures are below -35 degrees Celsius and are located on Ellesmere Island and on Axel Heiberg Island and south of the Boothia Peninsula in Nunavut. The highest mean January...

The plate contains four maps: Annual Winds, March Winds, August Winds and Annual Maximum Wind Speed. For each of the first three maps the frequency of wind, the mean speed of wind, and the frequency of calms are shown. On all three maps the frequency scale is 1 millimetre equals 2 percent. These...

The plate contains four maps showing the mean river freeze-over date, the mean lake freeze-over date, the mean river ice-free date and the mean lake ice free date. The four maps depict, in a general way, the average dates on which freshwater bodies in Canada become completely ice-covered in the...

Precipitation is derived from water vapour in the air, and it includes all forms of moisture falling on the earth's surface. Condensed water vapour accumulates in clouds, and precipitation occurs when the constituent ice crystals or water droplets grow too large to resist gravitational attraction...

The map shows the location of the snow course stations and the agencies that operate them. Most Canadian snow courses are operated by the federal Department of Fisheries and the Environment and the provincial government departments concerned with water resources. Though the principles of snow...

The plate contains four maps of 10 minute rainfalls (in millimetres) for a 2 year return period, a 5 year return period, a 10 year return period and a 25 year return period. Each map has a detailed inset of the Vancouver area. These four maps were not analyzed for the mountainous parts of Canada...

The plate contains four maps of 24 hour rainfalls (in millimetres) for a 2 year return period, a 5 year return period, a 10 year return period and a 25 year return period. Each map has a detailed inset of the Vancouver area. These four maps were not analyzed for the mountainous parts of Canada in...

The plate contains four maps of 60 minute rainfalls (in millimetres) for a 2 year return period, a 5 year return period, a 10 year return period and a 25 year return period. Each map has a detailed inset of the Vancouver area. These four maps were not analyzed for the mountainous parts of Canada...

The plate contains four maps. The first map shows the location of recording rain gauges used in the map and their number of years of record. The three other maps show the ratio 6-hour/24-hour rainfall extremes, the ratio 48-hour/24-hour rainfall extremes and the ratio 72-hour/24-hour rainfall...

Contained within the 1st Edition (1906) of the Atlas of Canada is a plate that shows 11 maps. Two maps at the top of this plate presenting isothermal lines for summer and for the entire year. The isotherms for summer display the great northern "loop" of the summer isotherm of 55 degrees...

The map represents the mean value (in millimetres) of the annual loss of water through the evaporation process from the surfaces of open water bodies, such as ponds and shallow lakes and reservoirs based on the 10-year period 1957 to 1966. The greatest mean annual lake evaporation (more than 900...

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...

The map shows the mean maximum depth of snow in centimetres, the standard deviation of the mean maximum depth of snow, and the mean date of mean maximum depth of snow. The information shown on the map is compiled from 1961 – 1970 snow course data in conjunction with 1955 – 1972 snow depth data....

The map shows isolines on four different dates: 1) the day of the year when there are less than or equal to 2.5 centimetres of snow that occurs and remain absent for 7 or more days; 2) the standard deviation of the mean date of snow cover loss; 3) the day of year when greater than or equal to 2.5...

The map shows the mean daily temperatures based on the 30-year period 1941-1970 for the warmest month in Canada. Although, the most direct and the most intense incoming solar radiation occurs in June, there is a lag in the warming of the Earth’s surface. As a result the warmest month in Canada is...

The map shows the annual snowfall (in centimetres) based on the 30-year period 1941-1970. Snowfall is measured by inserting a ruler into the new snow at several points to obtain its depth and to estimate the degree of drifting or scouring that has occurred. The water equivalent of snowfall for...

The plate contains four maps: (1) map of the global solar radiation network and sunshine recorder network; (2) annual global solar radiation; (3) June cloudless day radiation; and (4) mean annual net radiation. Stations recorded data to the end of 1970. Solar and net radiation are measured from a...

The Atmospheric Environment Service has no network density limitations for stations reporting precipitation. As general guidance it is suggested that gauge separations should be about 15 miles (24 kilometres) in rural areas; a higher density is desirable in more heavily populated areas, and in...