The climate is classified as humid continental, with cold winters and warm summers. The area receives an average of 48 inches of precipitation per year, with the majority falling as rain. Hydrology constituents include the Presumpscot River, which runs through the town, and numerous smaller streams and creeks. Outdoor recreation opportunities abound in Falmouth, with a variety of parks and trails to explore. Highlights include the Falmouth Nature Preserve, which offers hiking and birdwatching opportunities, and the town's multiple beaches, including the popular Mackworth Island State Park. Additionally, the Presumpscot River is a popular spot for kayaking and canoeing.
Falmouth receives approximately 1235mm of rain per year, with humidity levels near 78% and air temperatures averaging around 8°C. Falmouth has a plant hardyness factor of 5, 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.