Twelvemile C water temperature
Twelvemile C, Petersburg, Alaska · River
The current water temperature at Twelvemile C is 10.6 °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 160 data points since July 23, 2026.
Lowest recorded value: 9.3 °C on September 15, 2026 · highest value: 14.9 °C on August 22, 2026.
In September, temperatures have ranged between 9.3 °C and 12.5 °C.
The current value is 0.7 °C below the September average of this series.
Nearby waters
Frequently asked questions
Can you swim at Twelvemile C right now?
The current water temperature is 10.6 °C. See live swimming conditions, weather and quality in the BrrChecker app.
How warm is the water at Twelvemile C?
Currently 10.6 °C (updated continuously).
How warm is at Twelvemile C in September?
In September, the water temperature recently averaged 11.3 °C.
When is the water warmest at Twelvemile C?
Across the measurement record, July is on average the warmest month (13.3 °C).
