Marin

Goat Rock State Park Beach

Good to swim today.
Last sampled May 26, 2026 · 7 days ago

Recent samples within safe ranges.

Plate I: Location

Ninety days of readings.

Log scale · MPN/100mL

Each dot is one sample taken by the monitoring agency. The dashed brick line marks the EPA single-sample limit.

SafeCautionUnsafe

Common questions.

Is Goat Rock State Park Beach safe to swim today?
Goat Rock State Park Beach is currently safe for swimming. Recent samples within safe ranges.
When was Goat Rock State Park Beach last tested?
The most recent water-quality sample at Goat Rock State Park Beach was collected on May 26, 2026 (7 days ago). California monitoring agencies test Bay Area beaches weekly during swim season (roughly May through October).
What is the bacteria level at Goat Rock State Park Beach?
The latest reading at Goat Rock State Park Beach shows 30-day enterococcus geomean at 10 MPN/100mL (EPA geomean limit: 35); enterococcus at 10 MPN/100mL (EPA single-sample limit: 104); and E. coli at 10 MPN/100mL (EPA single-sample limit: 235).
Does rain affect water quality at Goat Rock State Park Beach?
Yes. Heavy rainfall washes bacteria and pollutants from land into the water, raising contamination risk for 24–72 hours. The past 48 hours recorded 0.00 in of rain; the past 72 hours recorded 0.00 in. Our advisory threshold is ≥1.00 in over 48h (or ≥0.50 in over 72h) for enclosed or storm-drain beaches.
Where is Goat Rock State Park Beach located?
Goat Rock State Park Beach is located in the Marin area of the San Francisco Bay region (coordinates: 38.4408°N, 123.1250°W). You can get turn-by-turn directions via Google Maps or Apple Maps directly from this page.
How is the water quality data for Goat Rock State Park Beach collected?
Bacteria samples are collected by California state and county health agencies under the AB 411 Safe-to-Swim program and reported to the state's Safe-to-Swim database (data.ca.gov). Rainfall figures come from Open-Meteo forecast and archive data. Bay Area Swim aggregates both sources and updates every morning.

Also nearby

Data: California Safe-to-Swim (ODbL 1.0) · Open-Meteo — Precipitation (CC-BY 4.0) · Pipeline status

For general guidance only · Conditions change · Swim at your own risk