Union, Mississippi is a small town located in the eastern part of the state. It experiences a humid subtropical climate, characterized by hot, humid summers and mild winters. Summers in Union are often hot and humid, with average temperatures reaching the high 80s°F (around 31°C), while winters are generally mild, with temperatures hovering in the mid-50s°F (around 13°C).

Hydrologically, Union is situated in the Leaf River watershed, which provides a water source for the town and surrounding areas. The river is known for its diverse aquatic life and offers opportunities for fishing and boating enthusiasts. Additionally, the area is dotted with numerous small lakes and ponds, providing additional options for water-based activities.

Outdoor recreation opportunities in Union are abundant. The town is surrounded by woodlands, making it an ideal destination for hiking, camping, and bird-watching. There are also several parks and green spaces where visitors can enjoy picnicking, playing sports, or simply taking a leisurely stroll. The proximity to the Bienville National Forest further expands outdoor options, with opportunities for hunting, fishing, and wildlife observation. Overall, Union offers a pleasant climate and a variety of outdoor activities for nature lovers and outdoor enthusiasts.