There was frost on the ground in Armstrong on Labor Day morning. People at most Wilderness North locations likely missed out on this seasonal reality because lake temperatures are still relatively warm. Armstrong is a noteworthy frost location in Ontario.
Most days in the recent week were warmer than normal and cool mornings like on Monday and Tuesday are not likely in the coming week. Expect afternoon temperatures of 72 to 82 F (22 to 28C), which are well above average for this time of the year. Normal highs are around 63F (17C). A ridge of high pressure during the week will bring considerable sun and light winds, occasionally moderate in the afternoon.