Contra Costa County, California: hazard risk
FEMA rates Contra Costa County's overall risk Very High (score 99.5 of 100, higher than 99% of rated U.S. counties); 6 of its 16 hazards are rated Relatively High or Very High, led by riverine flooding, earthquake, landslide. Its storm record holds 415 events since 1950.
FEMA's rating for each hazard
These are FEMA's county-wide model ratings and this county's storm record. They are not an assessment of any property, address or building, and not insurance advice: a property's risk depends on its own elevation, construction and location.
FEMA gives each hazard its own rating, and a rating does not follow the score from one hazard to the next: a hazard with a higher score can carry a lower rating than another. The table sorts by FEMA's rating, then by score (0 to 100, the county against every other county for that hazard).
| Hazard | Risk rating | Score | Expected annual loss |
|---|---|---|---|
| Riverine Flooding | Very High | 99.5 | $412M |
| Earthquake | Relatively High | 99.7 | $519M |
| Landslide | Relatively High | 99.3 | $2.4M |
| Heat Wave | Relatively High | 98.3 | $18M |
| Drought | Relatively High | 94.6 | $2.8M |
| Lightning | Relatively High | 90.8 | $1.5M |
| Wildfire | Relatively Moderate | 97.6 | $11M |
| Coastal Flooding | Relatively Moderate | 66.0 | $1.0M |
| Tornado | Relatively Low | 49.9 | $1.4M |
| Tsunami | Relatively Low | 47.7 | $1.0M |
| Strong Wind | Relatively Low | 34.4 | $398K |
| Volcanic Activity | Very Low | 77.9 | $343 |
| Hail | Very Low | 33.0 | $157K |
| Winter Weather | Very Low | 9.2 | $8K |
| Avalanche | Very Low | 5.3 | $3 |
| Cold Wave | No Rating | 0.0 | $0 |
Source: FEMA National Risk Index, December 2025 release. A model of future loss, not a count of past events. FEMA's National Risk Index map.
What the record holds
| Hazard | Records | Deaths | Damage | Rank in state | Rank in U.S. |
|---|---|---|---|---|---|
| High wind and dust storms | 232 | 2 | $3.1M | 10th of 57 | 186th of 3,080 |
| Floods | 74 | 0 | $66M | 9th of 57 | 1174th of 3,080 |
| Heat | 27 | 2 | $28K | 17th of 57 | 786th of 3,076 |
| Wildfires | 18 | 0 | $12K | 20th of 57 | 141st of 2,972 |
| Hail | 14 | 0 | – | 9th of 57 | 2809th of 3,080 |
| Landslides and avalanches | 13 | 0 | $18M | 14th of 57 | 52nd of 2,278 |
| Winter storms | 7 | 0 | – | 41st of 57 | 2931st of 3,077 |
| Heavy rain | 5 | 2 | $143K | 40th of 57 | 1121st of 3,080 |
| Tornadoes | 5 | 0 | $486K | 14th of 57 | 2604th of 3,080 |
| Severe thunderstorm wind | 4 | 0 | $100K | 26th of 57 | 2954th of 3,080 |
| Extreme cold | 2 | 0 | – | 44th of 57 | 2720th of 3,076 |
Source: NOAA NCEI Storm Events Database, 1950 to 2026-06-30; damage in 2025 dollars. Search the record at NCEI.
The full Contra Costa County record: every hazard by year and month, the deadliest events and FEMA's declarations.