What is with these Rising Lake Levels? Posted March 13, 2015 The Great Lakes water levels have both seasonal changes and long term changes. In a normal year the water level of Lakes Michigan and Huron rise and fall about 11 inches. The high usually occurs in July and the low in February. The melting snow and spring rains cause the levels to rise until mid-summer. Then the water levels slowly drop as the water warms and evaporation takes place. When fall and winter arrive, the rate of evaporation increases, because the water is warmer than the cold dry winds from the northwest. The quicker the ice forms and the more lake it covers, the sooner the drop in water level is reversed. By February the lake level usually stabilizes before it rises again in the spring. (more…)
