Sf Bay A San Mateo Bridge near Foster City, California water temperature
Sf Bay A San Mateo Bridge near Foster City, California · Sea/Coast
The current water temperature at Sf Bay A San Mateo Bridge near Foster City is 20.6 °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 400 data points since July 22, 2026.
Lowest recorded value: 20.2 °C on September 1, 2026 · highest value: 22.9 °C on August 7, 2026.
In September, temperatures have ranged between 20.2 °C and 21.6 °C.
The current value is 0.1 °C below the September average of this series.
Nearby waters
Frequently asked questions
Can you swim at Sf Bay A San Mateo Bridge near Foster City right now?
The current water temperature is 20.6 °C. See live swimming conditions, weather and quality in the BrrChecker app.
How warm is the water at Sf Bay A San Mateo Bridge near Foster City?
Currently 20.6 °C (updated continuously).
How warm is at Sf Bay A San Mateo Bridge near Foster City in September?
In September, the water temperature recently averaged 20.7 °C.
When is the water warmest at Sf Bay A San Mateo Bridge near Foster City?
Across the measurement record, August is on average the warmest month (21.8 °C).
