Firehole River water temperature
Firehole River, Old Faithful, Ynp · River
The current water temperature at Firehole River is 9.7 °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 156 data points since July 23, 2026.
Lowest recorded value: 8.8 °C on September 8, 2026 · highest value: 19.1 °C on July 25, 2026.
In September, temperatures have ranged between 8.8 °C and 17.1 °C.
The current value is 3.4 °C below the September average of this series.
Nearby waters
More measuring points: Firehole River
Frequently asked questions
Can you swim at Firehole River right now?
The current water temperature is 9.7 °C. See live swimming conditions, weather and quality in the BrrChecker app.
How warm is the water at Firehole River?
Currently 9.7 °C (updated continuously).
How warm is at Firehole River in September?
In September, the water temperature recently averaged 13.1 °C.
When is the water warmest at Firehole River?
Across the measurement record, July is on average the warmest month (17.9 °C).
