Columbia River at Bonneville Dam Forebay, Washington water temperature
Columbia River at Bonneville Dam Forebay, Washington · River
The current water temperature at Columbia River at Bonneville Dam Forebay is 20.2 °C (as of September 9, 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 149 data points since July 22, 2026.
Lowest recorded value: 20.2 °C on September 8, 2026 · highest value: 22.2 °C on August 25, 2026.
In September, temperatures have ranged between 20.2 °C and 21.1 °C.
The current value is 0.4 °C below the September average of this series.
Nearby waters
Frequently asked questions
Can you swim at Columbia River at Bonneville Dam Forebay right now?
The current water temperature is 20.2 °C. See live swimming conditions, weather and quality in the BrrChecker app.
How warm is the water at Columbia River at Bonneville Dam Forebay?
Currently 20.2 °C (updated continuously).
How warm is at Columbia River at Bonneville Dam Forebay in September?
In September, the water temperature recently averaged 20.6 °C.
When is the water warmest at Columbia River at Bonneville Dam Forebay?
Across the measurement record, July is on average the warmest month (21.8 °C).
