Orange County, California: Natural Disaster Risk and History
Orange County, California has a Very High natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 99.8 out of 100, higher than about 99% of US counties, with earthquakes, inland (river and flash) flooding and wildfires scoring highest of its 18 hazards and $1.9 billion a year in expected losses.
OpenFEMA lists 41 federal disaster declarations that included Orange County since 1969, not counting 2 for COVID-19; the latest is FM-5679-CA (Norte Fire, declared 16 October 2026). NOAA's Storm Prediction Center recorded 32 tornadoes touching Orange County from 1950 to 2025.
Live weather alerts for California All official warnings Latest FEMA declarations
Population 3,183,647 Buildings worth $606 billion Area 959 sq mi Risk rank in California 4 of 58 FIPS 06059
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Earthquake | Very High | 99.9 | $1.0 billion | about once every 10 years | — |
| Inland flooding | Very High | 99.8 | $820 million | about 2.9 a year | 81 |
| Wildfire | Relatively High | 99.8 | $58 million | about once every 93 years | — |
| Landslide | Relatively High | 99.7 | $4.2 million | about 18 a year | — |
| Heat wave | Relatively High | 97.2 | $11 million | about 7.4 a year | 81 |
| Coastal flooding | Relatively High | 92.0 | $8.4 million | about 2.1 a year | — |
| Tornado | Relatively Moderate | 83.7 | $5.3 million | about once every 7.8 years | 22 |
| Hail | Relatively Moderate | 79.5 | $937,384 | about once every 9.6 years | 4 |
| Lightning | Relatively Moderate | 66.9 | $488,671 | about 7.4 a year | 200,032 strikes |
| Tsunami | Relatively Low | 56.9 | $2.5 million | about once every 2.6 years | 83 |
| Strong wind | Relatively Moderate | 52.3 | $652,575 | about once every 5.7 years | 6 |
| Drought | Relatively Low | 32.7 | $36,627 | about 63 a year | 2,569 |
| Avalanche | Very Low | 13.7 | $16 | about once every 100 years | 0 |
| Winter weather | Very Low | 1.3 | $133 | about once every 5.0 years | 3.2 |
| Cold wave | No Rating | 0.0 | — | — | 0 |
| Hurricane | No Rating | 0.0 | — | — | 0 |
| Ice storm | Not Applicable | — | — | — | — |
| Volcanic activity | Not Applicable | — | — | — | — |
Score: FEMA's percentile among US counties that face the hazard (higher = more risk). Expected loss: FEMA's modelled average yearly loss to buildings, people (as a statistical value) and crops. How often: FEMA's annualised frequency of the hazard in the county; for some hazards it counts event-days, so it is a rough guide, not a forecast. "Not Applicable" means FEMA does not model that hazard here.
Federal disaster declarations 41
Most common: Fire 20, Flood 11, Severe Storm 5, Earthquake 2.
| Decade | Declarations | Incident types |
|---|---|---|
| 1960s | 1 | Flood |
| 1970s | 2 | Flood ×2 |
| 1980s | 6 | Flood ×2, Fire ×2, Earthquake, Coastal Storm |
| 1990s | 8 | Severe Storm ×3, Fire ×2, Flood ×2, Earthquake |
| 2000s | 11 | Fire ×8, Severe Storm ×2, Hurricane |
| 2010s | 5 | Fire ×3, Flood ×2 |
| 2020s | 8 | Fire ×5, Flood ×2, Chemical |
The last 10
Widest declarations that included Orange County
- Hurricane Katrina Evacuation (2005, EM-3248-CA): 58 California counties designated.
- Severe Winter Storms, Flooding Landslides, Mud Flow (1995, DR-1046-CA): 57 California counties designated.
- Severe Winter Storms, Flooding, Landslides, and Mudslides (2023, EM-3592-CA): 43 California counties designated.
Named storms in its declarations: Hurricane Katrina (2005).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. California also had 30 statewide declarations with no county list.
Tornado record since 1950 32
| Tornadoes touching the county | 32 |
|---|---|
| Strongest-rated | (E)F3 ×1 |
| Peak month | January (8) |
| Deadliest | 9 Feb 1978, F3, 2 mi path, 0 killed, 6 injured |
| Longest path | 16 Mar 1977, F1, 10.9 mi path, 0 killed, 4 injured |
| Most recent | 19 Jan 2010, EF1, 4.6 mi path |
| Deaths / injuries on those paths | 0 / 13 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 16 | 14 | 1 | 1 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 1 | 4 | 3 | 6 | 14 | 3 | 1 | 0 |
Deaths and injuries are for each tornado's whole path, which can run beyond this county. F-scale ratings before February 2007, Enhanced Fujita (EF) after.
How Orange County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Orange County (this page) | — | Very High | 99.8 | Earthquake |
| Los Angeles County | 81 km | Very High | 100.0 | Earthquake |
| San Diego County | 121 km | Very High | 99.7 | Wildfire |
| Ventura County | 148 km | Relatively High | 99.4 | Wildfire |
| Riverside County | 163 km | Very High | 99.9 | Wildfire |
| San Bernardino County | 193 km | Very High | 99.8 | Landslide |
Nearest by distance between county centres. Every county in California, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively Low 24.9 |
|---|---|
| Community resilience | Very Low 16.3 |
| Community risk factor | 0.95 |
| Expected annual loss, all hazards | $1.9 billion |
FEMA scales expected losses up where social vulnerability is high (people who may find it harder to prepare, evacuate or recover) and down where community resilience is high. A factor above 1 raises the risk score. For social vulnerability a high rating is worse; for resilience a high rating is better.
Prepare for Orange County's main hazards
- Right now: National Weather Service alerts for California · all official warnings on Global Incident Tracker.
- Earthquake: Earthquakes today · Earthquake safety guide
- Inland flooding: Flood safety: why shallow water kills · Floods recorded
- Wildfire: US wildfires now · Wildfire smoke: what protects you
- Your property's flood zone: FEMA Flood Map Service Center ↗ — this page cannot tell you that.
- Official preparedness guidance: Ready.gov ↗ and your county emergency management office.
What this page shows, and what it misses
FEMA's National Risk Index rates a whole county against every other US county; it is a planning-level estimate for nationwide comparison, not a flood-zone map and not a substitute for a local risk assessment or the risk to one home. Declarations are presidential disaster, emergency and fire management declarations that named this county; state declarations and SBA or USDA designations are not included. Tornadoes are counted when the county is one of up to four listed on the track; 670 tornadoes that crossed a state line carry no county list in NOAA's file and are left out.
Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties - v1.20.0 (December 2025). Retrieved from https://services.arcgis.com/XG15cJAlne2vxtgt/ArcGIS/rest/services/National_Risk_Index_Counties/FeatureServer/0/query on November 2, 2026, 1:20 PM EST. This product uses the Federal Emergency Management Agency’s National Risk Index dataset API or downloadable datasets 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).
Federal Emergency Management Agency (FEMA), OpenFEMA Dataset: Disaster Declarations Summaries - v2, retrieved from https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries on November 2, 2026, 1:21 PM EST. 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).
Tornado records: NOAA/NWS Storm Prediction Center, Severe Weather Database, tornadoes 1950–2025 (https://www.spc.noaa.gov/wcm/data/1950-2025_actual_tornadoes.csv, downloaded 2 November 2026). Public domain; not endorsed by NOAA. Compiled by Global Incident Tracker.
Questions about Orange County
What natural disasters is Orange County, California most at risk from?
Orange County, California has a Very High natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 99.8 out of 100, higher than about 99% of US counties, with earthquakes, inland (river and flash) flooding and wildfires scoring highest of its 18 hazards and $1.9 billion a year in expected losses.
How many federal disaster declarations has Orange County had?
OpenFEMA lists 41 federal disaster declarations that included Orange County since 1969, not counting 2 for COVID-19; the latest is FM-5679-CA (Norte Fire, declared 16 October 2026). Another 30 California declarations were made statewide without a county list.
How many tornadoes have hit Orange County?
NOAA's Storm Prediction Center recorded 32 tornadoes touching Orange County from 1950 to 2025. The deadliest: 9 Feb 1978, F3, 2 mi path, 0 killed, 6 injured (deaths and injuries are for the whole path).
Is the National Risk Index a flood zone map?
No. The National Risk Index is a planning-level estimate for a whole county, built for nationwide comparison. It does not tell you the flood zone or the risk of a single property: for that, look up the address on FEMA's Flood Map Service Center (msc.fema.gov) and ask your local floodplain manager.