Ice Climate Normals for 1991-2020
Ice climatology is a long-term summary of the observations and measurements of ice conditions over a certain geographic marine region. Every 10 years, Environment and Climate Change Canada’s Canadian Ice Service (CIS) publishes updated Ice Climate Normals, which capture the latest 30-year sea and lake ice climatology for Canadian waters.
These normals are important in determining changes in Canadian ice data over time. The changes observed between the different climatological periods influence decision-making related to safety in Canada’s navigable waters and traditional on ice activities, and research and policies aimed at protecting Canada’s environment.
Comparing the 1991-2020 Ice Climate Normals to the previous set, which covers 1981-2010, shows that overall there has been a general decrease in sea and lake ice in our waters. In addition, ice is forming later in the season and breaking up earlier. However, it is important to note that this varies from region to region and there has been little to no change in some regions of Canada.
Various factors influence ice conditions, including air and water temperatures, winds, precipitation, water depth, currents, waves and tides. In the Canadian Arctic, the decline of sea ice is associated with warmer temperatures.
These normals demonstrate that climate change is having an impact on long-term trends in sea and lake ice.