2025-Dec-08
December 7 Water Levels Report
Lake Michigan-Huron is 7 inches below its level at this time last year.
From a month ago, the water levels on Lakes Superior, Michigan-Huron, St. Clair, Erie & Ontario are down 4, 4, 6, 5 & 2 inches, respectively. Lakes Superior & Ontario levels are up 1 & 3 inches from the same as last year, while Lakes Michigan-Huron, St. Clair & Erie are lower by 7, 5 & 6 inches, respectively, than they were at this time last year. Lakes Superior, Michigan-Huron, Lakes St. Clair, Erie & Ontario are 4, 11, 7, 5 & 3 inches below their long-term December averages. All the lakes remain well below their December record highs.
In a month, Lakes Superior & Michigan-Huron levels are predicted to fall by 3 & 1 inches, respectively. Lakes St. Clair, Erie & Ontario are all expected to rise by 1 inch.
Lake Ontario’s outflow through the St. Lawrence River is projected to be below average for December. Lake Superior’s outflow through the St. Marys River, Lake Michigan-Huron’s outflow through the St. Clair River, Lake St. Clair’s outflow through the Detroit River, and Lake Erie’s outflow through the Niagara River are projected to be near average for December.
With regard to the forecast graph below, and the more recently updated first graph in this report, the USACE is predicting that the most likely outcome is that the Lake Michigan-Huron level will continue to drop through December.Monthly mean water levels for the previous year and the current year to date are shown as a solid line on the hydrographs. A projection for the next six months is given as a dashed line. This projection is based on the present condition of the lake basin and anticipated future weather. The shaded area shows a range of possible levels over the next six months dependent upon weather variations. Current and projected levels (solid and dashed lines) can be compared with the 1918-2021 average levels (dotted line) and extreme levels (shown as bars with their year of occurrence). The legend below further identifies the information on the hydrographs.
