Weather conditions in the Upper Peninsula of Michigan in September can range from warm Indian summer days in the high 70 degrees and low 80s or can be rainy or even cold, foreshadowing the winter to come. The same is true in November, although visitors should plan on cool, possibly snowy weather in the latter month. The best procedure when traveling to the U.P. in the fall is to come prepared with a variety of different weight shirts, a warm jacket and sturdy shoes that can handle wet conditions, if necessary.
Here are some links that will help you monitor weather conditions in Marquette.