Each Great Lake is now at least four degrees warmer than the typical surface water temperature for this date.
While it wasn’t an extraordinarily warm summer, September was very warm compared to normal. The warm September has definitely kept all of the Great Lakes from cooling off as fast as usual. September was three to five degrees warmer than normal across Michigan.
October has only been around one degree warmer than normal so far, but we are about to have a really warm stretch into next week. High temperatures will be in the 70s, so the Great Lakes' water cooling will also be slow in October.