Indiana Dunes National Park hugs 15 miles of the southern shore of Lake Michigan and offers rare bird species, sandy beaches, and 15,000 acres that include 50 miles of trails across rugged dunes, wetlands, prairies, rivers, and forests. On average, July is the warmest month, and the highest recorded temperature was 105F in 1934. January is the coolest month, with the lowest recorded temperature of -25F in 1985. June receives the most precipitation, with an average rainfall of 4.66 inches.