BrrChecker

Sf Bay A San Mateo Bridge water temperature

Sf Bay A San Mateo Bridge, Foster City, California · Sea/Coast

The current water temperature at Sf Bay A San Mateo Bridge is 20.3 °C (as of September 21, 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.

20.3 °C
Measured: September 21, 2026 · continuously updated
💧 Water 20.3° · ☀️ Air 13.5° · high today 20.2°
Temperature trend of recent weeks
Sf Bay A San Mateo Bridge
Photo: Tobias from Hamburg, Germany · CC BY-SA 2.0 · Wikimedia Commons

Measurement series & statistics

This measurement series includes 383 data points since July 23, 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 0.3 °C below the September average of this series.

Nearby waters

Frequently asked questions

Can you swim at Sf Bay A San Mateo Bridge right now?
The current water temperature is 20.3 °C. See live swimming conditions, weather and quality in the BrrChecker app.

How warm is the water at Sf Bay A San Mateo Bridge?
Currently 20.3 °C (updated continuously).

How warm is at Sf Bay A San Mateo Bridge in September?
In September, the water temperature recently averaged 20.6 °C.

When is the water warmest at Sf Bay A San Mateo Bridge?
Across the measurement record, August is on average the warmest month (21.8 °C).

Open in the BrrChecker app

← All waters · Warmest beaches & coasts today · Water temperature in United States