|The weather in the Keweenaw is greatly influenced by Lake Superior. While it can be warm inland it is usually cool out on the big lake. On the other hand, "The Lake" is cool and severe thunderstorms are rare. The visibility is good on most days with 15 miles being the norm. Storms are easy to see and avoid. It is not at all like Lake Michigan where it is hazy and you have a hard time seeing the storms until it is too late.
A number of links have been provided to allow you to look at the weather systems and lake temperatures. This will enable you to decide how warm it will be out on the lake. The air temperature is usually within a few degrees of the surface temperature of the water.
WATER TEMPERATURE AND SURFACE CURRENT LINKS