Mill Valley, CA
Local storm history & FEMA National Risk Index data
Mill Valley is rated Relatively High for overall natural hazard risk — higher risk than most US counties — based on FEMA's National Risk Index for Marin County, CA. The county's highest-rated hazards are landslide, earthquake, and coastal flooding.
Storm events near Mill Valley
NOAA-recorded tornado, hail, and flood events within 25 miles of Mill Valley's center, 2016–2026 — the only hazards NOAA reports with exact coordinates, so these counts are specific to Mill Valley itself, not the whole county.
County-wide hazard risk
Every other hazard FEMA and NOAA track — including drought — is only scored at the county level. These are Marin County's FEMA National Risk Index scores, covering Mill Valley along with the rest of the county, not a Mill Valley-specific figure.
| Hazard | NRI score | Rating |
|---|---|---|
| Wildfire | 94.6 | Relatively Moderate |
| Inland Flooding | 96.5 | Relatively High |
| Coastal Flooding | 97.2 | Very High |
| Earthquake | 98.7 | Relatively High |
| Heat Wave | 74.6 | Relatively Low |
| Tornado | 18.6 | Very Low |
| Avalanche | — | Not Applicable |
| Cold Wave | 0 | No Rating |
| Drought | 51.6 | Relatively Low |
| Hail | 3.7 | Very Low |
| Hurricane | — | Not Applicable |
| Ice Storm | — | Not Applicable |
| Landslide | 99.2 | Relatively High |
| Lightning | 34.1 | Relatively Low |
| Strong Wind | 11.2 | Very Low |
| Tsunami | 69.2 | Relatively Moderate |
| Volcanic Activity | 63.5 | Very Low |
| Winter Weather | 4 | Very Low |
Source: FEMA National Risk Index v1.20.0, December 2025. See the methodology page for definitions, or the full Marin County risk profile for disaster declarations, social vulnerability, and climate projection data.
Other cities in Marin County:
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Frequently asked questions
What natural hazards is Mill Valley, CA at risk of?
Mill Valley is rated Relatively High for overall natural hazard risk by FEMA's National Risk Index — higher risk than most US counties. The highest-rated hazards for Marin County, where Mill Valley is located, are landslide, earthquake, and coastal flooding.
What is Mill Valley's biggest natural hazard risk?
Landslide is the highest-rated hazard for Marin County, where Mill Valley is located, scoring 99.2 out of 100 on FEMA's National Risk Index (rated "Relatively High").
Is Mill Valley a high-risk area for natural disasters?
Yes — Mill Valley carries higher risk than most US counties for overall natural hazard risk, per FEMA's National Risk Index rating of "Relatively High" for Marin County.
Has Mill Valley had tornadoes, hail, or flooding?
NOAA has recorded 44 hail, 313 inland flooding events within 25 miles of Mill Valley since 2016.