About Lake Monona

Lake Monona has a surface area of 3,274 acres and a maximum depth of 64'. The depth around Belleisle is much lower. Until dredging was done in 2013, some sections of Lagoon du Nord had a summer depth of less than 18"!

The historic high water level of 847.86' AMSL was set on June 16, 2008. Prior to that date, the record was 847.48 on June 15, 2000 with several other notable high-water events. Water levels can be somewhat regulated via the Babcock Park Dam. Dane County attempts to keep water levels in the summer between 844.7' and 845.2' and above 842.2' in the winter.

The average Winter freeze date for Lake Monona occurs on December 15th. The earliest freeze was recorded on 11/22/1880 while the latest was on 01/30/1932. The average thaw (break up) date for Lake Monona occurs on March 31st. the earliest thaw occured on 02/27/1998 while the latest occured on 05/04/1857.

Recent Water Periods


On August 20, 2018 after much of Madison received 5-10" of rain, Lake Monona responded by quickly rising to levels last seen in the spring.


Lake Monona Water levels from April 12, 2009 through April 12, 2010 at which point we saw the lowest lake levels in years.


Spring 2008 Lake Monona water levels peaked at 846.35' on April 26th primarily due to a record snow fall during the 2007/2008 winter.

Over the next 30 days, the water level dropped down toward the Statutory Summer Maximum as water moved through the Yahara watershed.

Very heavy rains in June resulted in a large increase in Lake Monona water levels. A new record was reached on June 16th, 2008 of 847.86'. The previous record high water lavel was 847.48' on June 15, 2000.