Bethany, Missouri has a humid continental climate. Summers are warm and humid, with temperatures averaging around 80°F, while winters are cold and snowy, with temperatures averaging around 30°F. The city is situated within the Grand River Watershed, which is primarily agricultural and experiences issues with nitrate and bacteria contamination in streams due to agricultural runoff. Outdoor recreation opportunities in Bethany include fishing and boating on the nearby Grand River, as well as hiking and camping at nearby state parks such as Wallace State Park and Pony Express Lake Conservation Area. The area also offers hunting opportunities for deer, turkey, and small game.