South San Francisco Bay at Dumbarton Bridge, California water temperature
South San Francisco Bay at Dumbarton Bridge, California · Sea/Coast
The current water temperature at South San Francisco Bay at Dumbarton Bridge is 20.9 °C (as of September 20, 2026, source: USGS).
The sea lags the air by weeks: the warmest water often arrives after the warmest days. Measured buoy values show this honestly.
Measurement series & statistics
This measurement series includes 402 data points since July 22, 2026.
Lowest recorded value: 20.5 °C on September 2, 2026 · highest value: 23.5 °C on August 14, 2026.
In September, temperatures have ranged between 20.5 °C and 22.7 °C.
The current value is 0.2 °C below the September average of this series.
Nearby waters
Frequently asked questions
Can you swim at South San Francisco Bay at Dumbarton Bridge right now?
The current water temperature is 20.9 °C. See live swimming conditions, weather and quality in the BrrChecker app.
How warm is the water at South San Francisco Bay at Dumbarton Bridge?
Currently 20.9 °C (updated continuously).
How warm is at South San Francisco Bay at Dumbarton Bridge in September?
In September, the water temperature recently averaged 21.1 °C.
When is the water warmest at South San Francisco Bay at Dumbarton Bridge?
Across the measurement record, August is on average the warmest month (22.3 °C).
