The city experiences a humid subtropical climate with hot summers and mild winters. Summers are often hot and humid, with temperatures reaching the high 80s and occasionally the low 90s. Winters are relatively mild, with temperatures averaging in the 30s and 40s.
Okolona is not directly located on any major bodies of water, but it is part of the Ohio River Basin. The area is characterized by rolling hills and small streams that contribute to the region's hydrology.
Outdoor recreation opportunities in Okolona include several parks and green spaces, providing ample opportunities for walking, hiking, and picnicking. Jefferson Memorial Forest, the largest municipal urban forest in the United States, is also located nearby and offers opportunities for camping, fishing, and exploring nature trails.
Okolona receives approximately 1172mm of rain per year, with humidity levels near 79% and air temperatures averaging around 14°C. Okolona has a plant hardyness factor of 6, meaning plants and agriculture in this region thrive during a short period during spring and early summer. Most plants will die off during the colder winter months.