Lake Mendota, WI

As of 2026-10-12, Lake Mendota sits at 10.03 ft, which is high for this time of year. Over the past 30 days the level has risen 0.17 ft.

The most recent reading at Lake Mendota is 10.03 ft (2026-10-12), sourced from the U.S. Geological Survey. Readings on this page refresh automatically as the agency publishes new data.

The highest level for Lake Mendota in our records is 12.73 ft on 2000-06-05. The lowest is 0.20 ft on 1920-02-24. Our record covers about 110 years of readings.

Compared with every October in our records, the current level is higher than 83% of them, which we classify as high for this time of year. Seasonal comparison matters more than the raw number, because most reservoirs draw down predictably through late summer and refill over winter and spring.

Reservoir levels move for four main reasons: rainfall and runoff into the basin, releases through the dam for downstream water supply, power generation or flood control, evaporation during hot months, and seasonal drawdown schedules set by the operating agency. Lake Mendota has risen 0.17 ft over the past 30 days. For the operational reason on any given week, check the U.S. Geological Survey directly.

Lake Mendota is +0.26 ft compared with this date last year (10.03 ft today). The full-history chart above covers 110 years, with a record high of 12.73 ft and a record low of 0.20 ft.