Lake Ontario is still 13 C in the middle. Georgian Bay is cooler, but my heat pump could still get warmth from it. You're fine.
Georgian Bay - 45137 - Lake Huron - Current Conditions
Georgian Bay - 45137
11:00 PM EDT 21 October 2008Buoy position: 45.55N 81.00W
Wind (knots) NNE 23 gust 29 Pressure and tendency (kPa) 102.9 —
Wave height (m) 1.0 Air temperature (°C) 4
Wave period (s) 4 Water temperature (°C) 10