This morning we did a temp profile down to 10 meters (32.8 feet) using a UNH device as part of the NH Lakes Lay Monitoring Program.
http://extension.unh.edu/NH-Lakes-La...toring-Program
At a 95' deep site between Governors and Timber we recorded a constant 20.3 deg Centigrade (68.5 F) from 0.5 M down to 8.5 M (27.9 feet). The thermocline was at 9.5 M.
Probably the water is warmer in shallow areas.