After an unusually warm winter left the Great Lakes mostly free of winter ice, the surface temperatures of the lakes were near or above records for late June and early July. The map shows how much the water surface temperature was above or below average. Surface temperatures are 3°C to 5°C (6°F to 10°F) above normal. On July 10–12, the shallower coastal areas of Lakes Michigan, Huron, Erie, and Ontario ranged from 24°C to 29°C (75°F to 85°F). The only area below normal was the eastern portion of Lake Superior. July 9, 2020.