Mcnears beach

Each dot is one sample taken by the monitoring agency. Dashed lines mark each indicator's EPA single-sample limit; bars along the bottom show daily rainfall.

Common questions.

Is Mcnears beach safe to swim today?

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Mcnears beach is currently not safe for swimming. One or more bacteria readings exceeded EPA thresholds in the most recent sample. See the readings below for which indicator and how far above the limit.

When was Mcnears beach last tested?

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The most recent water-quality sample at Mcnears beach was collected on Sep 15, 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 Mcnears beach?

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The latest reading at Mcnears beach shows enterococcus at 121 MPN/100mL (EPA single-sample limit: 104); 30-day enterococcus geomean at 22 MPN/100mL (EPA geomean limit: 35); and E. coli at 20 MPN/100mL (EPA single-sample limit: 235).

Does rain affect water quality at Mcnears beach?

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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 Mcnears beach located?

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Mcnears beach is located in the Marin area of the San Francisco Bay region (coordinates: 37.9925°N, 122.4524°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 Mcnears beach collected?

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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.