Great Lakes: Tiny Tides, Big Changes

Do the Great Lakes have tides?

Technically, yes, but they’re so small they’re hardly noticeable. The gravitational pull of the sun and moon does create tiny, twice-daily changes in water level, but these are less than five centimeters at their peak.

What really drives water level changes in the Great Lakes is weather. Wind and barometric pressure can significantly alter lake levels, making these much larger fluctuations seem like tides. Additionally, long-term weather patterns, seasonal changes, and even short-term storms can impact water levels.

Another factor often mistaken for tides is a seiche, a large wave caused by wind pushing water to one end of a lake. Seiches can be several feet high and have a cycle similar to ocean tides, adding to the confusion.

So, while the Great Lakes do experience incredibly minor tides, it’s the weather and other factors that primarily shape their water levels.While Lake St. Clair is a large freshwater lake, it experiences water level fluctuations rather than tides. These variations are caused by wind, precipitation, and water flow from connecting rivers like the St. Clair River and Detroit River. Understanding current water levels is important for Sailors. You can find information on current water levels and forecasts from organizations like the National Oceanic and Atmospheric Administration (NOAA).

Here is how to find tides on the lake

https://www.tidetime.org/north-america/united-states/saint-clair-shores.htm