Summer & Winter. Summer if you are looking for slow and peaceful beach days, winter for dramatic views and virtually no one else around to disrupt your view.
People in the Midwest love their summers and will go to great lengths to enjoy them even if it means laying like sardines on tiny rectangles of sand they competed for. I believe this is because of our hard-hitting winters, we take whatever we can get. But there's good news - and it's Kenosha.
Lake Michigan's lakefront stretches through four Midwestern states, each offering slightly different views of the large body of water. After being to all the main beaches along the lakefront, personally I feel Kenosha offers the best views, cleanest and smoothest sand, most amenities, yet still has the fewest visitors - which makes for perfect lazy days along the water.
You could spend the entire day walking along the lakefront, there is enough distance to get in a good hike. It can be as long or as short as you want. There are public changing rooms/restrooms at the main beach (still consider bringing your own toilet paper as they run out in the busy season) and many attractions that cost very little or are free all along the lakefront. Park once by the beach and then use their electric streetcars to get around town in a two-mile loop. http://www.visitkenosha.com/attr...
For a list of other things you could do near the lake visit: