San Mateo County, California: hazard risk
FEMA rates San Mateo County's overall risk Relatively High (score 99.2 of 100, higher than 99% of rated U.S. counties); 5 of its 14 hazards are rated Relatively High or Very High, led by earthquake, landslide, riverine flooding. Its storm record holds 709 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 |
|---|---|---|---|
| Earthquake | Relatively High | 99.7 | $497M |
| Landslide | Relatively High | 99.7 | $4.4M |
| Riverine Flooding | Relatively High | 98.4 | $212M |
| Drought | Relatively High | 92.1 | $2.3M |
| Coastal Flooding | Relatively High | 91.8 | $8.7M |
| Wildfire | Relatively Moderate | 92.0 | $2.2M |
| Heat Wave | Relatively Moderate | 91.6 | $4.1M |
| Tsunami | Relatively Moderate | 70.8 | $7.2M |
| Lightning | Relatively Moderate | 68.2 | $549K |
| Tornado | Relatively Low | 30.6 | $627K |
| Strong Wind | Relatively Low | 20.6 | $222K |
| Hail | Very Low | 11.4 | $43K |
| Winter Weather | Very Low | 3.4 | $3K |
| 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 | 412 | 10 | $13M | 1st of 57 | 57th of 3,080 |
| Floods | 107 | 1 | $17M | 4th of 57 | 479th of 3,080 |
| Rip currents and high surf | 45 | 15 | $2.6M | 3rd of 57 | 23rd of 2,080 |
| Landslides and avalanches | 27 | 0 | $29M | 3rd of 57 | 18th of 2,278 |
| Heat | 21 | 9 | $14K | 19th of 57 | 794th of 3,076 |
| Severe thunderstorm wind | 20 | 0 | $90K | 2nd of 57 | 2677th of 3,080 |
| Winter storms | 15 | 0 | $19 | 33rd of 57 | 2684th of 3,077 |
| Heavy rain | 12 | 2 | $3.6M | 9th of 57 | 358th of 3,080 |
| Hail | 9 | 0 | $58 | 3rd of 57 | 2733rd of 3,080 |
| Wildfires | 8 | 1 | – | 26th of 57 | 184th of 2,972 |
| Extreme cold | 5 | 2 | $597K | 28th of 57 | 1874th of 3,076 |
| Lightning | 4 | 0 | – | 5th of 57 | 1319th of 3,080 |
| Tornadoes | 4 | 0 | $1.5M | 8th of 57 | 2465th of 3,080 |
Source: NOAA NCEI Storm Events Database, 1950 to 2026-06-30; damage in 2025 dollars. Search the record at NCEI.
The full San Mateo County record: every hazard by year and month, the deadliest events and FEMA's declarations.