Lake Monona water temperature
Lake Monona, Brittingham Beach · Lake
The current water temperature at Lake Monona is 17.6 °C (as of September 21, 2026, source: USGS · Proxy).
Lakes stratify in summer: bathing-warm on top, markedly colder a few metres down. Measurements are taken at the surface — right where you swim.
Measurement series & statistics
This measurement series includes 441 data points since July 23, 2026.
Lowest recorded value: 17.6 °C on September 21, 2026 · highest value: 26.7 °C on July 28, 2026.
In September, temperatures have ranged between 17.6 °C and 25.4 °C.
The current value is 6.1 °C below the September average of this series.
Nearby waters
More measuring points: Lake Monona
Frequently asked questions
Can you swim at Lake Monona right now?
The current water temperature is 17.6 °C. See live swimming conditions, weather and quality in the BrrChecker app.
How warm is the water at Lake Monona?
Currently 17.6 °C (updated continuously).
How warm is at Lake Monona in September?
In September, the water temperature recently averaged 23.7 °C.
When is the water warmest at Lake Monona?
Across the measurement record, July is on average the warmest month (24.5 °C).
