Straight from the Tap

Temperature of Lake Erie Equals Temperature of Tap Water


Did you notice that the water coming out of your tap was a little warmer today than it was a few days ago? You can thank summer and strong winds over Lake Erie for that.

A  heat wave of 90+ degree days over Memorial Day weekend increased the surface water temperatures of Lake Erie from the mid to low-50s to just over 70 degrees Fahrenheit. But the temperature near the bottom of the lake, where Cleveland Water’s intake cribs are located, stayed in the low 50s. This 20-degree temperature difference stayed put for the first two weeks of June and your tap water – which is always about the same temperature as the bottom waters of Lake Erie, was delivered to your house at about 52 degrees.

Then, between 6 and 8 p.m. on June 13, strong winds at speeds as high as 25 knots pushed from west to east across Lake Erie. This caused what’s known as a downwelling: the warm nearshore surface water got pushed down toward the bottom of the lake where it mixed with the colder water at the bottom of the lake. The result is surface water and bottom water temperatures that differ by only a few degrees.

Now, the deeper water of Lake Erie near our four intake cribs in the mid-60s - and so is the temperature of the water being delivered to your tap.

Map from Great Lakes Observing System Cleveland Water Buoy.