Sebago Lake Live Data Dashboard

Experience real-time monitoring of Maine's deepest lake. Track water levels, temperature fluctuations, and historical trends with our advanced dashboard system.

What Are Sebago Lake's Water Levels?

The dam that controls the level of Sebago Lake is owned by SAPPI (formerly SD Warren) in Westbrook. Sebago Lake experiences an annual water-level swing of roughly three feet — peaking near 266 feet in the spring and dipping to about 263 feet in the late fall and winter months.

Spring typically brings the highest water levels due to snowmelt and spring rains, while late summer and fall may see lower levels. These fluctuations affect shoreline access, boat launching, and dock usability, making real-time monitoring essential for lakefront property owners and recreational users.

What Is the Water Temperature of Sebago Lake?

Sebago Lake's water temperature varies significantly throughout the year. Summer temperatures typically range from 68°F to 75°F (20°C to 24°C) in surface waters, making it ideal for swimming, boating, and water sports. The lake's impressive depth of 316 feet creates a thermocline effect, where deeper waters remain consistently colder year-round.

Water Levels and Water Quality

Water levels in Sebago Lake play an important role in overall lake health. Because Sebago Lake is also the primary drinking water source for nearly 200,000 people in southern Maine, the lake is carefully monitored by organizations including the Portland Water District, Maine DEP, Lakes Environmental Association, and Sebago Clean Waters.