Natural disaster risk in Alameda County, California
California · population 1,678,284 · FIPS 06001
Overall: very high risk
Alameda County has a composite risk score of 99.8 out of 100 — among the highest 1% of US counties. It ranks 3 of 58 in California (1 = highest risk). Its highest-rated hazards are earthquake, inland (riverine) flooding, landslide.
Drought now: No: no drought or dryness
No. On the U.S. Drought Monitor map valid 13 October 2026, no part of Alameda County is in drought or abnormally dry (none of D0 to D4). That has been so for 25 weeks in a row.
Drought in Alameda County: the last 52 weeks · droughtmonitor.unl.edu
The U.S. Drought Monitor is jointly produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the United States Department of Agriculture, the National Oceanic and Atmospheric Administration and the National Aeronautics and Space Administration. Map courtesy of NDMC.
Risk, loss, vulnerability and resilience
| Measure | Rating and score |
|---|---|
| Overall risk Expected annual loss, adjusted for social vulnerability and community resilience. |
Very high 99.8 |
| Expected annual loss About $1.9 billion a year, on average, across all 18 hazards. |
Very high 99.8 |
| Social vulnerability Higher means people may find it harder to prepare and recover. |
Relatively low 27.5 |
| Community resilience Higher means a stronger ability to prepare, adapt and recover. |
Very high 91.2 |
Risk by hazard
FEMA's risk rating for each of 18 natural hazards in Alameda County, highest first. "Not applicable" means the hazard is not modelled here.
| Hazard | Risk rating and score |
|---|---|
| Earthquake | Very high 99 |
| Inland (riverine) flooding | Very high 99 |
| Landslide | Relatively high 99 |
| Heat wave | Relatively high 97 |
| Wildfire | Relatively high 97 |
| Coastal flooding | Relatively high 86 |
| Drought | Relatively moderate 85 |
| Tornado | Relatively moderate 65 |
| Tsunami | Relatively low 60 |
| Lightning | Relatively low 47 |
| Hail | Relatively low 35 |
| Volcanic activity | Very low 78 |
| Strong wind | Very low 11 |
| Avalanche | Very low 6 |
| Winter weather | Very low 4 |
| Cold wave | No rating |
| Hurricane | Not applicable |
| Ice storm | Not applicable |
FEMA disaster declarations for Alameda County
Federal declarations that designated Alameda County, since 1 Jan 2024 (the period this site keeps from OpenFEMA). Older declarations are in FEMA's own dataset.
Not since 1 Jan 2024: no FEMA disaster declaration in the records this site read names Alameda County.
All FEMA declarations in California, with estimated apply-by dates · Open FEMA deadlines
This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s). Dataset: Disaster Declarations Summaries - v2.
How to read these ratings
- Ratings run in five steps: very low, relatively low, relatively moderate, relatively high and very high. They compare a county with every other US county; they are not a measure of danger on their own.
- Scores run from 0 to 100 and are national percentiles. The bar shows the score: a score of 80 means a higher value than 80% of US counties.
- Overall risk combines the expected annual loss with social vulnerability and community resilience.
- Expected annual loss is the average yearly loss to buildings, people and agriculture the model expects from all 18 hazards.
- Social vulnerability describes how hard it may be for people to prepare for and recover from a disaster. Higher is worse.
- Community resilience describes a community's ability to prepare, adapt and recover. Higher is better.
- "Not applicable" means FEMA does not model that hazard there (for example, hurricanes far inland).
About this data
Source: FEMA National Risk Index, version 1.20, released December 2025, published by the Federal Emergency Management Agency (US public domain). About the National Risk Index. The index is a model of relative risk built from historical hazard records, what is exposed and community factors. It is not a forecast, it does not describe any single property, and it is not insurance or financial advice. For decisions about a specific address, check FEMA's flood maps and your local emergency management office.
Questions
What is the natural disaster risk in Alameda County, California?
FEMA's National Risk Index rates the overall risk in Alameda County as very high, with a score of 99.8 out of 100 (among the highest 1% of US counties). That is a comparison with other US counties, not a forecast.
What are the biggest natural hazards in Alameda County?
The hazards rated highest for Alameda County are earthquake (very high), inland (riverine) flooding (very high), landslide (relatively high).
What is the flood risk in Alameda County?
FEMA rates inland (river and rain) flooding risk in Alameda County as very high, and coastal flooding risk as relatively high. For a specific property, check the FEMA flood map and your local floodplain office.
Has Alameda County had a FEMA disaster declaration?
Not since 1 Jan 2024: no FEMA disaster declaration in the records this site read names Alameda County.
Is Alameda County in a drought?
No. On the U.S. Drought Monitor map valid 13 October 2026, no part of Alameda County is in drought or abnormally dry (none of D0 to D4). That has been so for 25 weeks in a row.
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