Carroll, Iowa is a small city located in the west-central part of the state. The climate in Carroll is characterized by cold winters and warm summers, with average temperatures ranging from 11°F in January to 75°F in July. The city lies within the Raccoon River watershed, with the Raccoon River and its tributaries providing the primary source of freshwater in the area. Hydrology constituents in the watershed include sediment, nutrients, and bacteria, which can impact water quality. Outdoor recreation opportunities in Carroll include several parks and trails for hiking, biking, and fishing. Swan Lake State Park, located just outside of Carroll, offers camping, boating, and swimming opportunities.