Light winds, abundant sunshine and unseasonable warm temperatures over the past week across Wisconsin and the western Great Lakes have resulted in Lake Michigan water temperatures warming 10 to 20 degrees. 

Below is a MODIS Sea Surface Temperature Image taken at 102 pm June 26th.  Lake Michigan sea surface temperatures are mostly in the middle to upper 60s from mid-lake to shore from Sheboygan south to the Illinois border.  Right along the shore in the shallower waters, the temperature was 70 in a few locations.

In contrast, below is a MODIS image taken at 1153 am about a week ago, on June 20th.  Sea surface temperatures at mid-lake were still mostly in the 50s. Some of the shallower waters east of downtown Milwaukee had warmed into the 60s at the time.

Lake Michigan sea surface temperatures typically peak in the 60s and 70s in August into early September.