Since I grew up in Grand Rapids MI downwind of Lake Michigan, I know how much the lake can affect local temperature and weather conditions in the area. AgWeb has a nice write-up of the impacts of the lake on farmers in northern Indiana, which is also affected by the lake, especially in winter and spring when winds are off the lake. You can read it here. In summer, with winds primarily from the south, lake effects are much smaller. Here in the Southeast, our biggest regional drivers of climate are the mountains and the coasts.
Below I’ve put a map of annual minimum temperatures and plant hardiness zomes to show the effect of the lake on temperatures in western Michigan. Areas near the lake do not get as cold as areas farther inland.
