Here is a graph of Lake Superior surface temps for the last 5 years. Notice the wide range (over 20 degrees F) between 2009 and 2012 in the early summer as the lake changes.
Yes, but it takes time. Been sailing and fishing Lake Superior for 32 years and I have yet to see where you can get any drastic change in a matter of one year.
We've seen surface temps at 50-53 around the Apostles in July and August. Go in a straight line up to the Slate Islands in Canadian waters and out in the middle of the lake it's 40-42. So it greatly depends on where you're sailing. If you stick to the bays and in the roughly 750 square miles of protected waters around the Apostles, you'll see little difference from last year even though those areas are the first to freeze and freeze the hardest during the winter.
The ice actually protects the lake and insulates it from severe weather extremes above.
Both 2011 and 2012 were very hot summers with mild winters in the Lake Superior Basin. So we saw some gradual rise, which is totally normal. 2013 was much cooler in the Basin thru the summer, with now a more normal winter where folks are able to walk out to the sea caves on the ice this year. Folks haven't been able to do that for the last 5 years because of abnormally mild winters. But to get a wide swing from one year to the next is how they say, "damn near impossible". At least I've never seen it in three decades of Lake Superior fishing.
That lake is too big and too deep to change overnight, or over winter. She contains more water than the rest of the Great Lakes combined. The summer temps are what changes it the most over time. Winter has very little to do with it.
What's going to be affected this coming spring and early summer is the rivers that drain from the Great Lakes. Superior isn't losing much of her water this year due to freeze-over and the snowfall in her watershed has exceeded anything seen since the 1930's. There's going to be some SERIOUS flow on the southern rivers this year.
