The climate in O'Brien is characterized by hot, humid summers and mild winters. The area experiences ample rainfall throughout the year, contributing to its lush vegetation and diverse ecosystem. As for hydrology constituents, O'Brien is surrounded by numerous springs, rivers, and lakes, making it a paradise for water enthusiasts. The Suwannee River and Ichetucknee River offer opportunities for kayaking, canoeing, fishing, and swimming. Additionally, O'Brien is known for its proximity to multiple natural springs, including the famous Ichetucknee Springs State Park, which attracts visitors with its crystal-clear waters and scenic trails. Outdoor enthusiasts will also find ample opportunities for hiking, biking, and camping in the surrounding forests and parks.
O-Brien receives approximately 1364mm of rain per year, with humidity levels near 89% and air temperatures averaging around 21°C. O-Brien has a plant hardyness factor of 8, meaning plants and agriculture in this region tend to thrive here all year round.