i had the pleasure of visiting sweden years ago and motoring the gota kanal. It was summer and the weather was good.
I have never sailed the Göta kanal my self, but I hear it is nice. In which direction did you go? West -> East or the other way?
the swedes we met told us that sweden has nine months of winter and three months of bad skating weather!
A very beautiful place.
That would be in the far north then and it is true there. In the south we have some really hot summers.