Mariposa County, California: Natural Disaster Risk and History
Mariposa County, California has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 86.4 out of 100, higher than about 86% of US counties, with landslides, wildfires and heat waves scoring highest of its 18 hazards and $38 million a year in expected losses.
OpenFEMA lists 22 federal disaster declarations that included Mariposa County since 1969, not counting 2 for COVID-19; the latest is FM-5503-CA (French Fire, declared 5 July 2024). NOAA's Storm Prediction Center recorded 3 tornadoes touching Mariposa County from 1950 to 2025.
Live weather alerts for California All official warnings Latest FEMA declarations
Population 17,060 Buildings worth $5.0 billion Area 1,478 sq mi Risk rank in California 43 of 58 FIPS 06043
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Landslide | Relatively High | 99.5 | $1.7 million | about 27 a year | — |
| Wildfire | Relatively High | 99.0 | $15 million | about once every 64 years | — |
| Heat wave | Relatively High | 98.4 | $11 million | about 6.1 a year | 62 |
| Winter weather | Relatively Moderate | 77.1 | $113,167 | about 13 a year | 239 |
| Drought | Relatively Moderate | 75.5 | $447,672 | about 83 a year | 2,324 |
| Inland flooding | Relatively Low | 70.8 | $8.4 million | about 2.1 a year | 58 |
| Lightning | Relatively Moderate | 69.2 | $302,329 | about 18 a year | 22,116 strikes |
| Earthquake | Relatively Low | 67.5 | $432,731 | about once every 35 years | — |
| Volcanic activity | Very Low | 58.6 | $17 | rarer than once in 1,000 years | 4 |
| Avalanche | Very Low | 40.5 | $171 | about once every 100 years | 0 |
| Strong wind | Very Low | 10.8 | $49,836 | about once every 21 years | 2 |
| Hail | Very Low | 6.6 | $11,836 | about once every 6.8 years | 5.6 |
| Tornado | Very Low | 6.4 | $18,388 | about once every 8.3 years | 2 |
| Cold wave | No Rating | 0.0 | — | — | 0 |
| Coastal flooding | Not Applicable | — | — | — | — |
| Hurricane | Not Applicable | — | — | — | — |
| Ice storm | Not Applicable | — | — | — | — |
| Tsunami | 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 22
Most common: Fire 9, Severe Storm 5, Flood 5, Hurricane 1.
| Decade | Declarations | Incident types |
|---|---|---|
| 1960s | 1 | Flood |
| 1970s | 1 | Drought |
| 1980s | 1 | Coastal Storm |
| 1990s | 2 | Severe Storm ×2 |
| 2000s | 4 | Fire ×3, Hurricane |
| 2010s | 7 | Fire ×4, Severe Storm ×2, Flood |
| 2020s | 6 | Flood ×3, Fire ×2, Severe Storm |
The last 10
Widest declarations that included Mariposa 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 Storms, Flooding, Mud and Landslides (1997, DR-1155-CA): 48 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 3
| Tornadoes touching the county | 3 |
|---|---|
| Strongest-rated | (E)F0 ×3 |
| Peak month | January (1) |
| Deadliest | — |
| Longest path | 2 Feb 2019, EF0, 0.2 mi path |
| Most recent | 2 Feb 2019, EF0, 0.2 mi path |
| Deaths / injuries on those paths | 0 / 0 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 3 | 0 | 0 | 0 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 0 | 0 | 1 | 0 | 0 | 1 | 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 Mariposa County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Mariposa County (this page) | — | Relatively Moderate | 86.4 | Landslide |
| Madera County | 42 km | Relatively High | 96.4 | Drought |
| Tuolumne County | 50 km | Relatively Moderate | 85.2 | Wildfire |
| Merced County | 84 km | Relatively High | 96.9 | Drought |
| Calaveras County | 90 km | Relatively Moderate | 86.6 | Wildfire |
| Fresno County | 94 km | Relatively High | 99.3 | Drought |
Nearest by distance between county centres. Every county in California, ranked.
Vulnerability and resilience
| Social vulnerability | Very High 93.0 |
|---|---|
| Community resilience | Relatively Low 21.3 |
| Community risk factor | 1.67 |
| Expected annual loss, all hazards | $38 million |
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 Mariposa County's main hazards
- Right now: National Weather Service alerts for California · all official warnings on Global Incident Tracker.
- Landslide: Landslides recorded
- Wildfire: US wildfires now · Wildfire smoke: what protects you
- Heat wave: Heatstroke warning signs
- 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 Mariposa County
What natural disasters is Mariposa County, California most at risk from?
Mariposa County, California has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 86.4 out of 100, higher than about 86% of US counties, with landslides, wildfires and heat waves scoring highest of its 18 hazards and $38 million a year in expected losses.
How many federal disaster declarations has Mariposa County had?
OpenFEMA lists 22 federal disaster declarations that included Mariposa County since 1969, not counting 2 for COVID-19; the latest is FM-5503-CA (French Fire, declared 5 July 2024). Another 30 California declarations were made statewide without a county list.
How many tornadoes have hit Mariposa County?
NOAA's Storm Prediction Center recorded 3 tornadoes touching Mariposa County from 1950 to 2025.
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.