Lake Erie Water Levels


Since the last glaciers retreated more than 10,000 years ago, Great Lakes water levels have varied dramatically. The difference between the amount of water coming into a lake and the amount going out is the determining factor in whether the water level will rise, fall, or remain stable.  When several months of above-average precipitation occur with cooler, cloudy conditions that cause less evaporation, the levels gradually rise. Likewise, prolonged periods of lower-than-average precipitation and warmer temperatures typically result in lowering of water levels.

Lake Erie experienced record high water levels in 2019

Why do water levels fluctuate?

There are three kinds of water level fluctuations: short-term, seasonal, and long-term. Click below to learn about how these fluctuations impact Lake Erie water levels. 

Short-term fluctuations

Some water level fluctuations are short-term and are due to winds or changes in barometric pressure. These short-term fluctuations, usually lasting from a couple of hours to several days, can be very dramatic and due to storms or ice jams. Storm surge or wind-set up is when high winds from one direction can push the water level up at one end of the lake and make the level drop by a corresponding amount at the opposite end. When the wind subsides abruptly the water level will often oscillate back and forth like a pendulum until it stabilizes again. Similar to water sloshing back and forth in a bowl, this phenomenon is known as a seiche. Lake Erie is most susceptible to storm surges and seiches due to its east-west orientation in an area of prevailing westerly winds and its generally shallow western end.

Seasonal fluctuations

Seasonal fluctuations range on average from 12 to 18 inches from winter lows to summer highs. The Great Lakes are generally at their lowest levels in the winter months. In the fall and early winter, when the air above the lakes is cold and dry and the lakes are relatively warm, evaporation is greatest. As the snow melts in the spring, runoff to the lakes increases.  Evaporation from the lakes is least in the spring and early summer when the air above the lakes is warm and moist and the lakes are cold. At times, condensation on the lake surface replaces evaporation. With more water entering the lakes than leaving, the water level rises. 

Long-term fluctuations

Long-term fluctuations occur over periods of consecutive years and have varied dramatically since water levels have been recorded for the Great Lakes. Continuous wet and cold years will cause water levels to rise. Conversely, consecutive warm and dry years will cause water levels to decline. Long-term fluctuations are shown on the hydrograph under Tracking Water Levels below. A hydrograph is a plot of water levels versus time. Global warming and a phenomenon known as the ‘greenhouse effect’ could cause significant changes in long-term lake levels. Although debatable, most predictions indicate that global warming would cause prolonged declines in average lake levels into the future. Besides natural climatic variability and potential man-made climate change, other factors can affect long-term fluctuations, including changes in consumptive use, channel dredging or encroachment and movement of the earth’s crust.


NOAA’S Tides and Current’s map provides real-time information on Erie’s water levels, air temperature, water temperature, wind speed, relative humidity, and more. 

Lake Erie Hydrograph

A hydrograph is a plot of lake levels versus time. This Hydrograph shows monthly average water levels for Lake Erie from 1918 to 2018. Long-term fluctuations are evident in this figure, with decades of above- and below-average water levels. 

Water levels are higher now than they used to be

Earlier decades, such as the 1930s and 1940s, had lower lake levels than later decades, such as the 1980s and 2010s. The most recent decade of higher water levels occurred after an extended period of very low lake levels.

Average monthly water levels for Lake Erie

This figure also displays the annual cycle of water levels. Water levels on all Great Lakes rise in the spring and summer due primarily to snowmelt runoff and low evaporation rates, and decline in the fall due to high evaporation rates from the temperature difference between the air (cold) and water (still warm from summer months). On average, the highest lake levels are seen between May and July.

This table displays average, record high, and record low lake levels for Lake Erie on annual and seasonal time scales. 


Presque Isle State Park’s manager, Matt Greene and a Pennsylvania DEP chief talk about water levels at the peninsula.