2020 Annual Climate Trends and Impacts Summary for the Great Lakes Basin

Coordinated by a partnership between climate services organizations in the U.S. and Canada, this product provides a synthesis report summarizing the previous years’ climate trends, events, new research, assessments, and related activities in the Great Lakes Region. This product is a contribution to the U.S.-Canada Great Lakes Water Quality Agreement, through Annex 9 on Climate Change Impacts, and to the national climate assessment processes in the U.S. and Canada. It should be cited as: Environment and Climate Change Canada and the U.S. National Oceanic and Atmospheric Administration. 2020 Annual Climate Trends and Impacts Summary for the Great Lakes Basin. 2021.

2020 Document
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During the 2020 reporting period, several notable events and trends were observed across the Great Lakes basin, including periods of very high temperatures in summer and fall, and extreme rainfall events that led to flooding in the winter and spring. Water levels on the Great Lakes continued to be very high, with Lake Superior, Lake Michigan-Huron, and Lake Erie reaching new record-high monthly mean levels multiple times. Locations around the basin experienced coastal flooding and erosion due to high water levels and low ice cover. Despite near-average precipitation in 2020, multiple years of above-average precipitation in the basin have cumulatively contributed to high water level conditions on the Great Lakes in recent years. At 19.5% areal coverage, Great Lakes maximum ice cover in 2020 was the 4th lowest on record.

Contributing Partners

Environment and Climate Change Canada
Great Lakes Environmental Research Laboratory
Great Lakes Integrated Sciences and Assessments
Great Lakes Water Quality Agreement
Midwestern Regional Climate Center
National Oceanic and Atmospheric Administration
Northeast Regional Climate Center



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