Petroleum County, Montana
Natural disaster risk, federal disaster history and flood insurance facts.
Petroleum County, Montana has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 99% of US counties. It ranks 54th of 56 counties in Montana. The costliest hazards here are lightning, cold waves and inland flooding. FEMA estimates about $1.6 million a year in expected losses, or roughly $3,321 per resident. Since 1986 it has been included in 10 federal disaster or emergency declarations for natural events (8 major disasters). The most recent was in July 2024 (severe winter storm and flooding). Only 1 home here carries federal flood insurance.
FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.
Top risks in Petroleum County
- Go indoors when you hear thunder.
- Use surge protectors for electronics.
- Insulate pipes in outside walls, crawl spaces and garages.
- Know how to shut off the main water valve.
- Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
- Price a flood policy now. Most new federal policies take 30 days to start.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Lightning | 69.9 | $538K | ||
| Cold wave | 32.4 | $505K | ||
| Inland flooding | 2.0 | $398K | ||
| Wildfire | 66.5 | $142K | ||
| Hail | 9.5 | $31K | ||
| Winter weather | 12.2 | $11K | ||
| Heat wave | 5.3 | $7K | ||
| Strong wind | 1.6 | $6K | ||
| Tornado | 2.5 | $5K | ||
| Drought | 17.7 | $2K | ||
| Earthquake | 1.7 | $2K | ||
| Ice storm | 0.5 | $353 | ||
| Landslide | 13.6 | $55 |
Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is relatively low and community resilience is very low in FEMA's measures.
Federal disaster history
Recent disasters nationwide ›Declarations by decade
Federal declarations for natural events that included Petroleum County. 2020s bar runs to November 2026.
By type
Most recent
Montana also had 36 statewide declarations that did not name single counties.
Storm history since 1962
Tornado risk by county ›The National Weather Service has logged 239 storm reports in Petroleum County since 1962, with 1 death and 1 injury and about $1 million in reported damage. The strongest on record here was an F2 tornado on August 7, 1962.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| Aug 7, 1962 | F2 | – | 0 / 0 |
| Jul 23, 1992 | F0 | – | 0 / 0 |
| Jun 22, 2002 | F0 | Winnett | 0 / 0 |
| Jul 8, 2002 | F0 | Winnett | 0 / 0 |
| Jun 28, 2005 | F0 | Winnett | 0 / 0 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| Aug 23, 2014 | Flood | Winnett | $515K |
| Jun 9, 2016 | Hail | Winnett | $500K |
| Jul 24, 1999 | Thunderstorm Wind | Winnett | $20K |
| Jun 6, 1994 | Hail | Winnett | $5K |
| Aug 7, 1962 | Tornado | – | $3K |
| Jul 4, 2008 | Thunderstorm Wind | Winnett | $200 |
Source: NOAA Storm Events Database, county-based reports through Jul 14, 2026. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.
Flood insurance in Petroleum County
Check your address flood zone ›National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.
Homes in Petroleum County
Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 311 housing units.
Compare in Montana
All 56 ›| Largest counties | Overall risk | Top hazard |
|---|---|---|
| Yellowstone County | Inland flooding | |
| Gallatin County | Earthquake | |
| Missoula County | Inland flooding | |
| Flathead County | Inland flooding | |
| Cascade County | Inland flooding | |
| Lewis and Clark County | Cold wave | |
| Ravalli County | Wildfire | |
| Silver Bow County | Cold wave |
Neighboring counties
| County | Overall risk | Declarations |
|---|---|---|
| Fergus County | 8 | |
| Rosebud County | 13 | |
| Musselshell County | 13 | |
| Phillips County | 8 | |
| Garfield County | 10 |
Common questions about Petroleum County
What is the biggest natural hazard in Petroleum County?
Lightning has the highest expected yearly losses in Petroleum County, about $538,294 a year in FEMA's estimate. Cold wave is second at $505,021.
How many federal disasters has Petroleum County had?
Petroleum County has been included in 10 federal disaster or emergency declarations for natural events since 1986, including 8 major disasters. The most recent was Severe Winter Storm and Flooding in July 2024.
Is Petroleum County a high-risk place to live?
Its overall rating is Very Low, 54th highest of 56 in Montana. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.
Do I need flood insurance in Petroleum County?
Standard home insurance does not cover flooding. About 1 in 500 homes in Petroleum County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.
How many tornadoes has Petroleum County had?
NOAA records list 8 tornadoes in Petroleum County since 1950. The strongest was an F2 tornado on August 7, 1962. The weather service has also logged 115 hail reports and 24 floods here.
Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.