Lake Michigan water temperature
Lake Michigan, Winthrop Harbor Buoy, IL · Lake
The current water temperature at Lake Michigan is 18.3 °C (as of September 20, 2026, source: NOAA NDBC).
Lakes stratify in summer: bathing-warm on top, markedly colder a few metres down. Measurements are taken at the surface — right where you swim.
Water quality
Official EPA rating: goodMeasurement series & statistics
This measurement series includes 584 data points since July 22, 2026.
Lowest recorded value: 8.1 °C on July 28, 2026 · highest value: 23.4 °C on September 4, 2026.
In September, temperatures have ranged between 8.6 °C and 23.4 °C.
The current value is 0.3 °C below the September average of this series.
Nearby waters
More measuring points: Lake Michigan
Frequently asked questions
Can you swim at Lake Michigan right now?
The current water temperature is 18.3 °C. See live swimming conditions, weather and quality in the BrrChecker app.
How warm is the water at Lake Michigan?
Currently 18.3 °C (updated continuously).
How warm is at Lake Michigan in September?
In September, the water temperature recently averaged 18.6 °C.
When is the water warmest at Lake Michigan?
Across the measurement record, July is on average the warmest month (20.5 °C).
How is the water quality at Lake Michigan?
The official classification is: good.
