Fremont, CA— fire, flood & earthquake hazard information
Fremont is a city in Alameda County in the San Francisco Bay Area, covering about 78.1 square miles. This page summarizes what official government maps show for Fremont: 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 Fremont’s area that falls inside each mapped zone.
View Fremont on the interactive map → to check any specific address, free.
Wildfire hazard severity zones
Per CAL FIRE's Fire Hazard Severity Zone maps, 1% 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 | 1% |
| Moderate severity zone | less than 1% |
FEMA flood zones
24% of Fremont 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); 3% is in the 0.2% annual chance (500-year) area. Federally backed mortgages in a Special Flood Hazard Area generally require flood insurance.
| Special Flood Hazard Area (100-yr) | 24% |
| Coastal high hazard (V/VE) | 5% |
| 0.2% annual chance (500-yr) | 3% |
Earthquake faults & seismic zones
The nearest mapped fault, the Hayward fault zone, is about 0.4 mi (0.7 km) from the center of Fremont. 5 named fault traces in the USGS Quaternary fault database cross its boundary. 50% of its area is in a state-designated liquefaction zone of required investigation. 14% is in an earthquake-induced landslide zone. 3% falls within an Alquist-Priolo earthquake fault zone, where new construction requires a fault study.
| Nearest mapped fault | Hayward fault zone — 0.4 mi (0.7 km) |
| Named fault traces crossing boundary | 5 |
| Liquefaction zone | 50% |
| Earthquake-induced landslide zone | 14% |
| Alquist-Priolo fault zone | 3% |
Dam inundation, aircraft noise & air quality
40% of Fremont lies within a state-reviewed dam-failure inundation area; annual average fine-particle (PM2.5) concentration across its census tracts is 8.4 μg/m³, and its composite pollution burden ranks around the 43th percentile statewide.
| Dam-failure inundation area | 40% |
| Annual PM2.5 (tract average) | 8.4 μg/m³ |
| Pollution burden percentile (statewide) | ~43 |
Frequently asked questions
- Is Fremont in a wildfire hazard severity zone?
- Per CAL FIRE's Fire Hazard Severity Zone maps, 1% is in a High zone, less than 1% is in a Moderate zone. The remainder of its area is outside currently designated zones.
- Is Fremont in a FEMA flood zone?
- 24% of Fremont 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); 3% is in the 0.2% annual chance (500-year) area. Federally backed mortgages in a Special Flood Hazard Area generally require flood insurance.
- What earthquake faults and seismic zones affect Fremont?
- The nearest mapped fault, the Hayward fault zone, is about 0.4 mi (0.7 km) from the center of Fremont. 5 named fault traces in the USGS Quaternary fault database cross its boundary. 50% of its area is in a state-designated liquefaction zone of required investigation. 14% is in an earthquake-induced landslide zone. 3% falls within an Alquist-Priolo earthquake fault zone, where new construction requires a fault study.
- How do I check a specific address in Fremont?
- Use the free sitelume interactive map at https://sitelume.com — search any Fremont address to see which mapped zones it falls in, layer by layer.
Nearby in Alameda 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.