Napa, CA— fire, flood & earthquake hazard information
Napa is a city in Napa County in the San Francisco Bay Area, covering about 18.1 square miles. This page summarizes what official government maps show for Napa: 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 Napa’s area that falls inside each mapped zone.
View Napa on the interactive map → to check any specific address, free.
Wildfire hazard severity zones
Per CAL FIRE's Fire Hazard Severity Zone maps, less than 1% is in a Moderate zone. The remainder of its area is outside currently designated zones.
| Moderate severity zone | less than 1% |
FEMA flood zones
19% of Napa lies within a FEMA Special Flood Hazard Area (1% annual chance, zones A/AE/AH/AO); 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) | 19% |
| 0.2% annual chance (500-yr) | 5% |
Earthquake faults & seismic zones
The nearest mapped fault, the West Napa fault, is about 1.0 mi (1.7 km) from the center of Napa. 1 named fault trace in the USGS Quaternary fault database cross its boundary. 11% falls within an Alquist-Priolo earthquake fault zone, where new construction requires a fault study.
| Nearest mapped fault | West Napa fault — 1.0 mi (1.7 km) |
| Named fault traces crossing boundary | 1 |
| Alquist-Priolo fault zone | 11% |
Dam inundation, aircraft noise & air quality
23% of Napa lies within a state-reviewed dam-failure inundation area; annual average fine-particle (PM2.5) concentration across its census tracts is 9.6 μg/m³, and its composite pollution burden ranks around the 47th percentile statewide.
| Dam-failure inundation area | 23% |
| Annual PM2.5 (tract average) | 9.6 μg/m³ |
| Pollution burden percentile (statewide) | ~47 |
Frequently asked questions
- Is Napa in a wildfire hazard severity zone?
- Per CAL FIRE's Fire Hazard Severity Zone maps, less than 1% is in a Moderate zone. The remainder of its area is outside currently designated zones.
- Is Napa in a FEMA flood zone?
- 19% of Napa lies within a FEMA Special Flood Hazard Area (1% annual chance, zones A/AE/AH/AO); 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 Napa?
- The nearest mapped fault, the West Napa fault, is about 1.0 mi (1.7 km) from the center of Napa. 1 named fault trace in the USGS Quaternary fault database cross its boundary. 11% falls within an Alquist-Priolo earthquake fault zone, where new construction requires a fault study.
- How do I check a specific address in Napa?
- Use the free sitelume interactive map at https://sitelume.com — search any Napa address to see which mapped zones it falls in, layer by layer.
Nearby in Napa 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.