Muir Beach, CA— fire, flood & earthquake hazard information
Muir Beach is a unincorporated community in Marin County in the San Francisco Bay Area, covering about 0.5 square miles. This page summarizes what official government maps show for Muir Beach: CAL FIRE fire hazard severity zones, FEMA flood zones, state seismic hazard zones, dam inundation areas, airport noise contours, and air-quality indicators. Figures are the share of Muir Beach’s area that falls inside each mapped zone.
View Muir Beach on the interactive map → to check any specific address, free.
Wildfire hazard severity zones
Per CAL FIRE's Fire Hazard Severity Zone maps, 42% is in a High zone, less than 1% is in a Moderate zone. The remainder of its area is outside currently designated zones.
| High severity zone | 42% |
| Moderate severity zone | less than 1% |
FEMA flood zones
9% of Muir Beach lies within a FEMA Special Flood Hazard Area (1% annual chance, zones A/AE/AH/AO); 5% is in a coastal high hazard zone (V/VE). Federally backed mortgages in a Special Flood Hazard Area generally require flood insurance.
| Special Flood Hazard Area (100-yr) | 9% |
| Coastal high hazard (V/VE) | 5% |
Earthquake faults & seismic zones
The nearest mapped fault, the San Andreas fault zone, is about 5.4 mi (8.7 km) from the center of Muir Beach.
| Nearest mapped fault | San Andreas fault zone — 5.4 mi (8.7 km) |
Dam inundation, aircraft noise & air quality
annual average fine-particle (PM2.5) concentration across its census tracts is 8.0 μg/m³, and its composite pollution burden ranks around the 30th percentile statewide.
| Annual PM2.5 (tract average) | 8.0 μg/m³ |
| Pollution burden percentile (statewide) | ~30 |
Frequently asked questions
- Is Muir Beach in a wildfire hazard severity zone?
- Per CAL FIRE's Fire Hazard Severity Zone maps, 42% is in a High zone, less than 1% is in a Moderate zone. The remainder of its area is outside currently designated zones.
- Is Muir Beach in a FEMA flood zone?
- 9% of Muir Beach lies within a FEMA Special Flood Hazard Area (1% annual chance, zones A/AE/AH/AO); 5% is in a coastal high hazard zone (V/VE). Federally backed mortgages in a Special Flood Hazard Area generally require flood insurance.
- What earthquake faults and seismic zones affect Muir Beach?
- The nearest mapped fault, the San Andreas fault zone, is about 5.4 mi (8.7 km) from the center of Muir Beach.
- How do I check a specific address in Muir Beach?
- Use the free sitelume interactive map at https://sitelume.com — search any Muir Beach address to see which mapped zones it falls in, layer by layer.
Nearby in Marin County
Sources: CAL FIRE Fire Hazard Severity Zones; FEMA National Flood Hazard Layer; USGS Quaternary Faults; CGS Seismic Hazard Zones & Alquist-Priolo zones; Cal OES dam inundation maps; county ALUC noise contours; CalEnviroScreen 4.0. Area shares are computed against each place’s Census TIGER boundary (last computed 2026-07-24). Boundaries and zone designations change; always verify with the issuing agency.