Isle Royale Forums

We are going out the second week of September. Is it likely we are going to see a lot of fog? I know it varies a lot but does that time of the year have more than normal ? Thanks

Usually mid-September is the time the weather starts to change. You see more north wind and deep blue skies when a Canadian high pressure moves in. Or more grey skies and rain when a cold front comes through. The big, summertime, sprawling high pressure systems, that can produce fog, usually don’t happen at this time of the year.

It's unlikely to see advective fog (caused when warm, moist air flows over a cool surface) because the land and water in the area will be at nearly it's warmest, and the air is cooling and tends to be drier that time of year. That type is quite common in June. You might, however, see some evaporative fog (cold air over water that is warmer than it) if the temp drops, especially in the mornings. That type of fog isn't as widespread, however, and tends to only be around the water itself.