Illinois River water temperature
Illinois River, Henry, Illinois · River
The current water temperature at Illinois River is 22.6 °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 96 data points since August 26, 2026.
Lowest recorded value: 22.6 °C on September 21, 2026 · highest value: 30.6 °C on September 4, 2026.
In September, temperatures have ranged between 22.6 °C and 30.6 °C.
The current value is 5.7 °C below the September average of this series.
Nearby waters
More measuring points: Illinois River
Frequently asked questions
Can you swim at Illinois River right now?
The current water temperature is 22.6 °C. See live swimming conditions, weather and quality in the BrrChecker app.
How warm is the water at Illinois River?
Currently 22.6 °C (updated continuously).
How warm is at Illinois River in September?
In September, the water temperature recently averaged 28.3 °C.
