How are the Chicago Lake Michigan water temperatures taken?
The Chicago area shore water temperature has been taken at the James W. Jardine Water Purification Plant near Navy Pier from a sensor 15 feet below the surface since 1965. A water temperature is also taken from a sensor near a water intake pipe at the Harrison-Dever Crib located about two miles offshore east of Navy Pier. The U.S. Coast Guard also provides shoreline readings at its stations at Calumet Harbor and Michigan City as well as other sites around the Great Lakes. Additionally, the National Oceanic and Atmospheric Administration operates a series of Great Lakes buoys. The nearest buoy is located 43 miles east/southeast of Milwaukee and reports hourly mid-lake water temperatures readings from a sensor two feet beneath the buoy.