Redwood City, CA— fire, flood & earthquake hazard information
Redwood City is a city in San Mateo County in the San Francisco Bay Area, covering about 19.3 square miles. This page summarizes what official government maps show for Redwood City: 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 Redwood City’s area that falls inside each mapped zone.
View Redwood City on the interactive map → to check any specific address, free.
Wildfire hazard severity zones
Per CAL FIRE's Fire Hazard Severity Zone maps, 3% of Redwood City is in a Very High fire hazard severity zone. The remainder of its area is outside currently designated zones.
| Very High severity zone | 3% |
FEMA flood zones
34% of Redwood City lies within a FEMA Special Flood Hazard Area (1% annual chance, zones A/AE/AH/AO); 9% is in a coastal high hazard zone (V/VE); 5% 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) | 34% |
| Coastal high hazard (V/VE) | 9% |
| 0.2% annual chance (500-yr) | 5% |
Earthquake faults & seismic zones
The nearest mapped fault, the San Jose fault, is about 0.9 mi (1.5 km) from the center of Redwood City. 3 named fault traces in the USGS Quaternary fault database cross its boundary. 49% of its area is in a state-designated liquefaction zone of required investigation. 2% is in an earthquake-induced landslide zone.
| Nearest mapped fault | San Jose fault — 0.9 mi (1.5 km) |
| Named fault traces crossing boundary | 3 |
| Liquefaction zone | 49% |
| Earthquake-induced landslide zone | 2% |
Dam inundation, aircraft noise & air quality
4% of Redwood City lies within a state-reviewed dam-failure inundation area; annual average fine-particle (PM2.5) concentration across its census tracts is 8.2 μg/m³, and its composite pollution burden ranks around the 52th percentile statewide.
| Dam-failure inundation area | 4% |
| Annual PM2.5 (tract average) | 8.2 μg/m³ |
| Pollution burden percentile (statewide) | ~52 |
Frequently asked questions
- Is Redwood City in a wildfire hazard severity zone?
- Per CAL FIRE's Fire Hazard Severity Zone maps, 3% of Redwood City is in a Very High fire hazard severity zone. The remainder of its area is outside currently designated zones.
- Is Redwood City in a FEMA flood zone?
- 34% of Redwood City lies within a FEMA Special Flood Hazard Area (1% annual chance, zones A/AE/AH/AO); 9% is in a coastal high hazard zone (V/VE); 5% 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 Redwood City?
- The nearest mapped fault, the San Jose fault, is about 0.9 mi (1.5 km) from the center of Redwood City. 3 named fault traces in the USGS Quaternary fault database cross its boundary. 49% of its area is in a state-designated liquefaction zone of required investigation. 2% is in an earthquake-induced landslide zone.
- How do I check a specific address in Redwood City?
- Use the free sitelume interactive map at https://sitelume.com — search any Redwood City address to see which mapped zones it falls in, layer by layer.
Nearby in San Mateo 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.