Mississippi River Pool Lock and Dam 26 water temperature
Mississippi River Pool Lock and Dam 26, Alton, Illinois · River
The current water temperature at Mississippi River Pool Lock and Dam 26 is 26.6 °C (as of September 21, 2026, source: USGS).
A river can change temperature within hours — snowmelt, rain or power-plant operations show up immediately. That is why the measured value counts here, not an estimate.
Measurement series & statistics
This measurement series includes 94 data points since August 26, 2026.
Lowest recorded value: 26.6 °C on August 27, 2026 · highest value: 30.2 °C on September 5, 2026.
In September, temperatures have ranged between 26.6 °C and 30.2 °C.
The current value is 2.1 °C below the September average of this series.
Nearby waters
Frequently asked questions
Can you swim at Mississippi River Pool Lock and Dam 26 right now?
The current water temperature is 26.6 °C. See live swimming conditions, weather and quality in the BrrChecker app.
How warm is the water at Mississippi River Pool Lock and Dam 26?
Currently 26.6 °C (updated continuously).
How warm is at Mississippi River Pool Lock and Dam 26 in September?
In September, the water temperature recently averaged 28.7 °C.
