St Johns River water temperature
St Johns River, Marco Lake at Jacksonville, Florida · River
The current water temperature at St Johns River is 28.4 °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 180 data points since July 23, 2026.
Lowest recorded value: 28.4 °C on September 21, 2026 · highest value: 32.9 °C on July 24, 2026.
In September, temperatures have ranged between 28.4 °C and 32.2 °C.
The current value is 1.5 °C below the September average of this series.
Nearby waters
More measuring points: St Johns River
Frequently asked questions
Can you swim at St Johns River right now?
The current water temperature is 28.4 °C. See live swimming conditions, weather and quality in the BrrChecker app.
How warm is the water at St Johns River?
Currently 28.4 °C (updated continuously).
How warm is at St Johns River in September?
In September, the water temperature recently averaged 29.9 °C.
When is the water warmest at St Johns River?
Across the measurement record, July is on average the warmest month (31.2 °C).
