Petroleum County, Montana: Natural Disaster Risk and History
Petroleum County, Montana has a Very Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 1.3 out of 100, higher than about 1% of US counties, with lightning, wildfires and cold waves scoring highest of its 18 hazards and $1.6 million a year in expected losses.
OpenFEMA lists 10 federal disaster declarations that included Petroleum County since 1986, not counting 2 for COVID-19; the latest is DR-4801-MT (Severe Winter Storm and Flooding, declared 18 July 2024). NOAA's Storm Prediction Center recorded 8 tornadoes touching Petroleum County from 1950 to 2025.
Live weather alerts for Montana All official warnings Latest FEMA declarations
Population 496 Buildings worth $354 million Area 1,691 sq mi Risk rank in Montana 54 of 56 FIPS 30069
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Lightning | Relatively Moderate | 69.9 | $538,294 | about 29 a year | 13,063 strikes |
| Wildfire | Relatively Low | 66.5 | $141,608 | about once every 235 years | — |
| Cold wave | Relatively Low | 32.4 | $505,021 | about 7.7 a year | 146 |
| Drought | Very Low | 17.7 | $2,407 | about 71 a year | 1,792 |
| Landslide | Very Low | 13.6 | $55 | about once every 1.3 years | — |
| Winter weather | Very Low | 12.2 | $10,505 | about 17 a year | 319 |
| Hail | Very Low | 9.5 | $31,398 | about 1.4 a year | 51 |
| Heat wave | Very Low | 5.3 | $6,792 | about 2.9 a year | 35 |
| Tornado | Very Low | 2.5 | $5,022 | about once every 8.8 years | 7 |
| Inland flooding | Very Low | 2.0 | $397,938 | about once every 1.2 years | 23 |
| Earthquake | Very Low | 1.7 | $1,793 | rarer than once in 1,000 years | — |
| Strong wind | Very Low | 1.6 | $6,039 | about once every 1.4 years | 27 |
| Ice storm | Very Low | 0.5 | $353 | about once every 67 years | 0 |
| Avalanche | Not Applicable | — | — | — | — |
| 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 10
Most common: Flood 4, Severe Storm 3, Fire 2, Hurricane 1.
| Decade | Declarations | Incident types |
|---|---|---|
| 1980s | 1 | Flood |
| 2000s | 2 | Hurricane, Fire |
| 2010s | 5 | Flood ×2, Severe Storm ×2, Fire |
| 2020s | 2 | Severe Storm, Flood |
The last 10
Widest declarations that included Petroleum County
- Hurricane Katrina Evacuation (2005, EM-3253-MT): 56 Montana counties designated.
- Severe Storms and Flooding (2011, DR-1996-MT): 49 Montana counties designated.
- Wildfires (2000, DR-1340-MT): 48 Montana 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. Montana also had 18 statewide declarations with no county list.
Tornado record since 1950 8
| Tornadoes touching the county | 8 |
|---|---|
| Strongest-rated | (E)F2 ×1 |
| Peak month | July (5) |
| Deadliest | — |
| Longest path | 7 Aug 1962, F2, 2 mi path |
| Most recent | 7 Jul 2020, EF0, 0.1 mi path |
| Deaths / injuries on those paths | 0 / 0 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 7 | 0 | 1 | 0 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 0 | 1 | 1 | 0 | 1 | 3 | 0 | 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 Petroleum County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Petroleum County (this page) | — | Very Low | 1.3 | Lightning |
| Musselshell County | 70 km | Very Low | 17.0 | Wildfire |
| Fergus County | 75 km | Relatively Low | 45.1 | Cold wave |
| Garfield County | 97 km | Very Low | 2.5 | Wildfire |
| Golden Valley County | 108 km | Very Low | 1.0 | Wildfire |
| Treasure County | 125 km | Very Low | 0.5 | Wildfire |
Nearest by distance between county centres. Every county in Montana, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively Low 27.4 |
|---|---|
| Community resilience | Very Low 12.9 |
| Community risk factor | 0.97 |
| Expected annual loss, all hazards | $1.6 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 Petroleum County's main hazards
- Right now: National Weather Service alerts for Montana · all official warnings on Global Incident Tracker.
- Lightning: Weather alerts for Montana
- Wildfire: US wildfires now · Wildfire smoke: what protects you
- Cold wave: Carbon monoxide in winter · Power outages now
- 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 Petroleum County
What natural disasters is Petroleum County, Montana most at risk from?
Petroleum County, Montana has a Very Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 1.3 out of 100, higher than about 1% of US counties, with lightning, wildfires and cold waves scoring highest of its 18 hazards and $1.6 million a year in expected losses.
How many federal disaster declarations has Petroleum County had?
OpenFEMA lists 10 federal disaster declarations that included Petroleum County since 1986, not counting 2 for COVID-19; the latest is DR-4801-MT (Severe Winter Storm and Flooding, declared 18 July 2024). Another 18 Montana declarations were made statewide without a county list.
How many tornadoes have hit Petroleum County?
NOAA's Storm Prediction Center recorded 8 tornadoes touching Petroleum 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.