Natrona County, Wyoming: Natural Disaster Risk and History
Natrona County, Wyoming has a Relatively Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 68.9 out of 100, higher than about 68% of US counties, with winter storms, wildfires and landslides scoring highest of its 18 hazards and $33 million a year in expected losses.
OpenFEMA lists 6 federal disaster declarations that included Natrona County since 1978, not counting 2 for COVID-19; the latest is DR-4739-WY (Flooding, declared 11 September 2023). NOAA's Storm Prediction Center recorded 39 tornadoes touching Natrona County from 1950 to 2025.
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Population 79,870 Buildings worth $19 billion Area 5,430 sq mi Risk rank in Wyoming 3 of 23 FIPS 56025
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Winter weather | Very High | 97.1 | $1.2 million | about 17 a year | 330 |
| Wildfire | Relatively Moderate | 93.0 | $2.7 million | about once every 427 years | — |
| Landslide | Relatively Moderate | 91.7 | $83,866 | about 3.3 a year | — |
| Earthquake | Relatively Low | 82.8 | $2.6 million | about once every 346 years | — |
| Cold wave | Relatively Moderate | 82.5 | $5.0 million | about 1.7 a year | 33 |
| Avalanche | Relatively Moderate | 81.6 | $593,667 | about once every 10 years | 3 |
| Inland flooding | Relatively Moderate | 74.7 | $19 million | about once every 1.2 years | 23 |
| Lightning | Relatively Moderate | 67.3 | $523,810 | about 38 a year | 212,581 strikes |
| Ice storm | Relatively Low | 41.7 | $66,858 | about once every 67 years | 1 |
| Hail | Relatively Low | 41.1 | $217,208 | about once every 1.9 years | 20 |
| Tornado | Relatively Low | 36.9 | $874,676 | about once every 2.2 years | 24 |
| Drought | Very Low | 21.0 | $6,071 | about 79 a year | 2,429 |
| Heat wave | Very Low | 17.2 | $54,019 | about once every 7.8 years | 0 |
| Strong wind | Very Low | 5.6 | $43,647 | about once every 3.2 years | 12 |
| Coastal flooding | Not Applicable | — | — | — | — |
| Hurricane | Not Applicable | — | — | — | — |
| Tsunami | 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 6
Most common: Fire 4, Flood 2.
| Decade | Declarations | Incident types |
|---|---|---|
| 1970s | 1 | Flood |
| 2000s | 2 | Fire ×2 |
| 2010s | 2 | Fire ×2 |
| 2020s | 1 | Flood |
The last 6
Widest declarations that included Natrona County
- Severe Storms, Flooding & Mudslides (1978, DR-557-WY): 12 Wyoming counties designated.
- Flooding (2023, DR-4739-WY): 1 Wyoming counties designated.
- Station Fire (2015, FM-5115-WY): 1 Wyoming counties designated.
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. Wyoming also had 1 statewide declaration with no county list.
Tornado record since 1950 39
| Tornadoes touching the county | 39 |
|---|---|
| Strongest-rated | (E)F2 ×5 |
| Peak month | June (17) |
| Deadliest | 11 Jun 1962, F2, 52 mi path, 0 killed, 4 injured |
| Longest path | 11 Jun 1962, F2, 52 mi path, 0 killed, 4 injured |
| Most recent | 23 Jun 2023, EF1, 10.8 mi path |
| Deaths / injuries on those paths | 0 / 8 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 25 | 8 | 5 | 0 | 0 | 0 | 1 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 0 | 7 | 5 | 11 | 4 | 4 | 6 | 2 |
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 Natrona County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Natrona County (this page) | — | Relatively Low | 68.9 | Winter weather |
| Converse County | 105 km | Very Low | 31.4 | Wildfire |
| Johnson County | 121 km | Very Low | 19.3 | Wildfire |
| Washakie County | 127 km | Very Low | 24.4 | Landslide |
| Carbon County | 141 km | Very Low | 42.7 | Avalanche |
| Fremont County | 149 km | Relatively Low | 59.7 | Landslide |
Nearest by distance between county centres. Every county in Wyoming, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively Low 20.5 |
|---|---|
| Community resilience | Relatively Moderate 57.3 |
| Community risk factor | 0.89 |
| Expected annual loss, all hazards | $33 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 Natrona County's main hazards
- Right now: National Weather Service alerts for Wyoming · all official warnings on Global Incident Tracker.
- Winter weather: Power outages now · Carbon monoxide in winter
- Wildfire: US wildfires now · Wildfire smoke: what protects you
- Landslide: Landslides recorded
- 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 Natrona County
What natural disasters is Natrona County, Wyoming most at risk from?
Natrona County, Wyoming has a Relatively Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 68.9 out of 100, higher than about 68% of US counties, with winter storms, wildfires and landslides scoring highest of its 18 hazards and $33 million a year in expected losses.
How many federal disaster declarations has Natrona County had?
OpenFEMA lists 6 federal disaster declarations that included Natrona County since 1978, not counting 2 for COVID-19; the latest is DR-4739-WY (Flooding, declared 11 September 2023). Another 1 Wyoming declarations were made statewide without a county list.
How many tornadoes have hit Natrona County?
NOAA's Storm Prediction Center recorded 39 tornadoes touching Natrona County from 1950 to 2025. The deadliest: 11 Jun 1962, F2, 52 mi path, 0 killed, 4 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.