Uncertainties: trend - Maximum percent ice cover in the Great Lakes: Difference from 50-year mean (1973-2023)

Six lollipop charts highlight deviations in maximum percent ice cover on the five Great Lakes (Lake Michigan, Lake Erie, Lake Superior, Lake Huron, and Lake Ontario) from 1973-2023. The difference in lake ice cover is shown for each lake and across the entire system compared to the 50-year mean (1973-2023). Positive oriented lollipops are shown in shades of blue, and negative oriented lollipop are shown in shades of purple. Across all five of the great lakes, 2023 maximum percent ice coverage was below the 50 year average, with basin wide ice coverage being 59% below average in 2023. Most lakes show a general pattern of lower ice coverage through time, although ice cover is highly variable from year to year.