New-Madison, Ohio experiences a humid continental climate characterized by hot summers and cold winters. Average temperatures range from 20°F (-6.7°C) in winter to 85°F (29.4°C) in summer. Precipitation is evenly distributed throughout the year, with an annual average of 40 inches (101.6 cm).

Situated near the Greenville Creek, hydrology plays a significant role in New-Madison. The creek contributes to a diverse ecosystem and provides opportunities for fishing and boating. Outdoor enthusiasts can explore the picturesque surrounding areas with activities like hiking, camping, and birdwatching in the nearby Shawnee Prairie Preserve. The tranquil nature trails and picnic spots make it an ideal location for family outings and relaxation. New-Madison, Ohio offers a pleasant climate and ample outdoor recreation opportunities for nature lovers and adventurers alike.