Fairfax, Missouri has a humid subtropical climate with four distinct seasons. Summers are hot and humid, while winters are cold with occasional snowfall. The town is situated near the Tarkio River, which flows into the Missouri River. The hydrology constituents of the area include sediment, nutrients, and pesticides from agricultural runoff. Outdoor recreation opportunities in Fairfax include hiking at nearby parks such as Squaw Creek National Wildlife Refuge and Nodaway Valley Conservation Area, fishing in the Tarkio River, and golfing at the Rock Port Golf and Country Club. Fairfax also hosts an annual summer festival, the Fairfax Fair, which includes a parade, carnival rides, and live music.