Macomb, United States offers 1 beach perfect for sunbathing, surfing, swimming, and more. Macomb, Illinois, United States, is known for Western Illinois University. The best time to travel to Macomb, United States, is in late spring or early fall when the average air temperature is around 60-75°F, though there are no significant bodies of water to note average water temperatures. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!