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 most climatologically stations is estimated by simply assuming the freshly fallen snow has a density of 0.10 gram per cubic centimetre. On the average, this is a sound approximation over large parts of the country, but variations from 0.05 to 0.15 are common from storm to storm, and in the drier regions the average density is probably closer to 0.08 gram per cubic centimetre. Since 1961 the Nipher shielded snow gauge has been used at principal stations to derive the water equivalent of snowfalls. Snow collected in the gauge is melted to obtain this value. At remote stations snowfall is measured in terms of water equivalent by automatic and storage gauges, such as the Fischer and Porter Gauge and the Sacramento Gauge. The data mapped were obtained from the 1941-1970 period, using both synoptic and climatological stations. The representativeness of many stations for regional snowfall measurements is subject to question. Extreme exposure to the wind and the danger of interference from snow control and snow removal equipment are principal dangers at airports, where many principal meteorological stations are situated. The locations of climatological stations are biased by the availability of volunteer observers.

This statistic shows the average snowfall for Canada from 1971 to 2000, by city. Victoria, Canada averaged 43.8 centimeters of snowfall annually from 1971 to 2000.

This map shows the average maximum snow depth in centimetres computed over 18 winter seasons (1979 to 1997). Over southern Canada this usually occurs in January or February, while the time of maximum accumulation occurs much later in mountain areas and in the Arctic. The main features of the map are the pronounced maximum in snow accumulation over the western Cordillera, where snow depths can exceed several metres, with a secondary maximum over Quebec and Labrador. These maxima are related to their proximity to oceans, which act as sources of moisture and winter storms, and to the orographic effect of the mountains in the case of western Canada. The two maxima are linked by a band of higher snow accumulation that follows the boreal forest zone; this is a preferred track for winter storms. To the north of this zone is the relatively shallow snow cover of the Arctic (low snowfall with extensive wind packing). To the south, the depth of snow is limited by the shorter accumulation season and the substantial sublimation of snow over the Canadian Prairies.

This data contains location information for 1 of Ontario’s snow monitoring networks:Surface Water Monitoring Centre (SWMC)Snow course data is collected by:conservation authoritiesOntario Power GenerationMinistry of Natural Resources (MNR) districtsData is collected twice a month from November 15 until May 15. The Surface Water Monitoring Centre uses this data to assess:current snow coverfrozen ground conditionssnowpackpotential snowmeltcontributions to streamflowThe snow data is located in a corporate water and climate database. This data helps MNR and conservation authorities assess the potential for flood at the local and provincial scale.Additional DocumentationOntario Snow Survey location and data - Data Dictionary (Excel)Historic and Current Snow Survey Metadata (1933-2024) (CSV) StatusPlanned: fixed date has been established upon or by which the data will be created or updatedMaintenance and Update FrequencyAnnually: data is updated every yearContactSurface Water Monitoring Centre, surface.water@ontario.ca

Over southern Canada maximum snow depth usually occurs in January or February, while the time of maximum accumulation occurs much later in mountain areas and in the Arctic. The main features of the map are the pronounced maximum in snow accumulation over the western Cordillera (British Columbia and Yukon), where snow depths can exceed several metres, with a secondary maximum over Quebec and Labrador. These maxima are related to their proximity to oceans, which acts as sources of moisture and winter storms, and to the orographic effect of the mountains in the case of western Canada. The two maxima are linked by a band of higher snow accumulation that follows the boreal forest zone; this is a preferred track for winter storms. To the north of this zone is the relatively shallow snow cover of the Arctic (low snowfall with extensive wind packing). To the south, the depth of snow is limited by the shorter accumulation season and the substantial sublimation of snow over the Canadian Prairies. An inset map shows the average maximum snow depth where it is deepest in Canada: central Vancouver Island (British Columbia). A second inset shows the distribution of Canada's daily snow depth station network, 1997.

Contained within the 4th Edition (1974) of the Atlas of Canada is a set of three maps relating the effects and dependency of vegetation on environmental variables. One map shows the average annual potential evapotranspiration in inches from ground and plant surfaces for areas where there is a continuous vegetation cover and sufficient soil moisture for plant use. The second map shows the average annual water deficit in inches where, during parts of the growing season, soil moisture is insufficient to supply enough moisture for theoretically full plant growth. The last map shows the accumulated number of degree-days. For the purpose of this map degree-days are calculated from the base temperature of 42 degrees F/5.6 degrees C. The growing season is defined on this map as the number of days with an average temperature over 42 degrees F/5.6 degrees C.

Contained within the 5th Edition (1978 to 1995) of the National Atlas of Canada has a large that shows the extent of permafrost and abundance of ground ice; mapping units are based on physiographic regions. Point data on map give permafrost temperature and thickness for specific sites. The second, smaller, map shows the mean annual ground temperatures. Graphs show four shallow temperature profiles (to 25 metres depth), and four deep temperature profiles (to several hundred metres depth).

Contained within the 4th Edition (1974) of the Atlas of Canada is a set of two maps. One shows soil temperature classes and the second shows soil moisture regimes and subclasses. These maps are supplemented by a text giving detailed definitions for both soil temperature classes and soil moisture regimes and sub classes.

Contained within the 5th Edition (1978 to 1995) of the National Atlas of Canada is a map that shows the annual sum of heating degree days (an indicator of building heating needs). Data for period 1941 to 1970. Companion sheet to Frost-Free Period, Growing Degree-Days, Last Frost in Spring and First Frost in Autumn.