30-year Climatic Ice Atlases
The Canadian Ice Service has been analyzing ice in Canadian waters for more than 40 years. We have compiled statistics for the 30-year climatological periods for different regions of Canada. There are statistics for the East Coast of Canada (Atlantic Canada); the Great Lakes (including Lake Michigan); the Western Arctic, the Eastern Arctic and Hudson Bay, as well as the north combined: Eastern Arctic, Western Arctic and Hudson Bay, referred as the Northern Canadian Waters.
Information on the ice is based on weekly, bi-weekly or monthly charts. In the south, the maps have always been produced weekly so our statistics reflect that. In the north the maps were produced weekly during the active summer shipping season but over winter the production was reduced to monthly in previous years so the statistics are only available monthly. In the legend of the maps, there is a note that says how many years of data went into the statistics.
The type of information available is:
- The median of ice concentration
- The median of predominant ice type when ice is present
- The frequency of presence of sea ice (%)
- Median of Old Ice Concentration
- Frequency of Presence of Old Ice 1 to 10/10 (%)
- Frequency of Presence of Old Ice Concentration 4 to 10/10 (%)
- Median of Ice Concentration When Ice is Present
- Dates of freeze-up and break-up
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