Decatur, Alabama is located in the Tennessee River Valley and has a humid subtropical climate. Summers are hot and humid, with temperatures reaching into the 90s. Winters are mild, with occasional snow and temperatures averaging in the 40s. The Tennessee River runs through Decatur, providing both recreational opportunities and a source of drinking water. Hydrology constituents in the river include sediment, nutrients, and bacteria. Outdoor recreation opportunities in Decatur include hiking and biking trails, fishing and boating on the Tennessee River, and golfing at several local courses. The Wheeler National Wildlife Refuge, just outside of Decatur, offers additional outdoor recreation opportunities and the chance to view a variety of wildlife.