Great Lakes Water Levels, Temperature and News

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Sunset over Lake Michigan. Photo by Rafi Wilkerson, National Park Service (Public Domain).

The warmer than average water temperature of Lake Michigan gave a little added boost to the lake-effect snow and rain we had Friday.

25-Year Record of the Water temperature of Lake Michigan

This is the 25-year record of the water temperature of Lake Michigan. The black line is 2021, the red line is 2016. The current water temperature (early Sat. AM) of 53.3° (at the mid-Lake Michigan buoy) is the second warmest it has been on 11/13 over the last 25 years. The relatively warm water can add a little boost to lake-effect snowfall in early winter if this trend continues. However, a cool pattern from now through the end of the year should bring the temperature of the lake back closer to average.

The links below and the pins on the map reveal plots of the current year’s daily lake levels (blue) compared with last year’s levels (black) and last year’s annual average (dark red). The monthly averages are shown as a step plot through the daily averages. Plotted in the background are the coordinated (official) averages (green), record highs (cyan), and record lows (brown) per month as documented here along with additional water level data.

Graph of the Water Level of Lake Superior

The water level of Lake Superior is down 5″ in the last month. The pattern has been dry for a good portion of the Lake Superior basin. Marquette has had 5.31″ of precipitation since Sept 1. That’s just 58% of average. Superior is down 13″ in the last year and is now 3″ below the November average water level. The lower water level has reduced the water moving down the St. Marys River from Lake Superior into Lake Huron. The flow on the river early Saturday was 46,700 cubic feet per second. Average flow is 69,000 cfs. That’s just 67.7% of average flow. Will less water moving down into Lake Huron…that will act to keep the water level of both Lakes Huron and Michigan lower.

Graph of the Water Level of Lake Michigan/Huron

The water level of Lake Michigan Huron is also down 5″ in the last month. The lakes are down 17″ in just the last year (that’s a lot!). The lakes are still 15″ above the average November level, but they are now 23″ below the high water mark of Nov. 1986. The lower water level is good news for Racine, Wisconsin – where they are working to clean up the Lake Michigan shore and the debris littered by a storm in January 2020 that produced 60 mph wind gusts and huge, destructive waves.

Graph of the Water Level of Lake Erie

The water level of Lake Michigan is unchanged in the last month and unchanged in the last year. The level is still 26″ above the average November level, but it’s 7″ below the highest November level of 1986. The St. Clair River that moves water from Lake Huron to Lake Erie is exactly at the average flow of 204,000 cfs.

Graph of the Water Level of Lake Ontario

The water level of Lake Ontario is up 3″ in the last month and up 9″ in the last year. The lake is now 12″ higher than the November average level, but is 13″ below the highest November level set in 1945.

Map of the Great Lakes Basin

Here’s a map of the Great Lakes basin – showing the drainage area for each of the Great Lakes. Here’s some current (Sat. AM) river flow readings: Grand River at Grand Rapids 4,540 cfs (avg. is 2,520 cfs), Kalamazoo River at Comstock 1,110 cfs (avg. is 756 cfs), Muskegon River at Croton 1,880 cfs (avg. is 1,820 cfs), St Joseph River at Niles 5,330 cfs (avg. is 2,430 cfs), Saginaw River at Saginaw 4,210 cfs (avg. is 2,890 cfs). In Wisconsin, the Fox River at Green Bay has a flow of 5,540 cfs, compared to an average flow of 4,490 cfs.

ALSO: A look back at the Wreck of the Edmund Fitzgerald. >>Photos: The SS Edmund Fitzgerald – from inception to sinking

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