Petroleum County, Montana
County storm and disaster record · FIPS 30069 · population 496 · 1,656 sq mi
NOAA's Storm Events Database holds 389 records for Petroleum County, Montana from 1950 through June 30, 2026, on 282 days; the most frequent are hail reports (115 records). The deadliest single record is the September 18, 1998 lightning: 1 death and 1 injury. FEMA has issued 12 declarations naming the county since 1986, 10 of them for natural hazards; the latest for a natural hazard was “Severe Winter Storm and Flooding” on July 18, 2024.
The record, 1950 to 2026
Storm records filed for the county each year (2026 to June 30, 2026). Before 1996 NOAA recorded only tornadoes (from 1950), thunderstorm wind and hail (from 1955).
- recorded, no damage figure
- under $100,000
- $100,000 or more
- $1 million or more
- $10 million or more, or a death
- $100 million or more, or 10 deaths
- a year's colour: its recorded damage or deaths
- a year with a death
- 1955: wind and hail recorded from 1955
- 1996: all 48 event types from 1996
- Storm records
- 389on 282 days, 1950 to June 30, 2026
- Deaths recorded
- 11 injuries
- Damage, 2025 dollars
- $1.4Mas filed (scale steps before 1993)
- Tornadoes
- 8strongest F2
- FEMA declarations
- 12latest 2024
Source: NOAA NCEI Storm Events Database, records through June 30, 2026 (file revision 20260918); damage converted to 2025 dollars with the BLS CPI-U. Search the record at NCEI. BLS consumer price index.
What hazards hit Petroleum County most?
The most frequent records are hail reports: 115 since 1963. 79% of its hail reports since 1963 fell in June and July. The rank column places the county among Montana's counties by days with a record per 1,000 square miles of land over each hazard's complete period.
| Hazard | Records | Days | First, last | Killed | Injured | Damage | Rank in state |
|---|---|---|---|---|---|---|---|
| Hail | 115 | 74 | 1963-2025 | 0 | 0 | $625K | 19 of 56 |
| Severe thunderstorm wind | 80 | 50 | 1986-2026 | 0 | 0 | $36K | 20 of 56 |
| Winter storms | 66 | 63 | 1996-2026 | 0 | 0 | $61K | 38 of 56 |
| High wind and dust storms | 41 | 37 | 1999-2026 | 0 | 0 | $47K | 45 of 56 |
| Drought | 36 | 36 | 2005-2026 | 0 | 0 | – | 7 of 56 |
| Floods | 24 | 23 | 1997-2023 | 0 | 0 | $642K | 8 of 56 |
| Extreme cold | 8 | 8 | 1997-2024 | 0 | 0 | – | 36 of 56 |
| Tornadoes | 8 | 7 | 1962-2020 | 0 | 0 | $24K | 15 of 56 |
| Wildfires | 5 | 5 | 2003-2017 | 0 | 0 | – | 14 of 56 |
| Heat | 2 | 2 | 2003-2007 | 0 | 0 | – | 12 of 56 |
| Heavy rain | 2 | 2 | 2008-2010 | 0 | 0 | – | 42 of 56 |
| Lightning | 1 | 1 | 1998-1998 | 1 | 1 | – | 15 of 56 |
| Fog, smoke and funnel clouds | 1 | 1 | 2004-2004 | 0 | 0 | – | 45 of 56 |
Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.
How many tornadoes has Petroleum County had?
NOAA records 8 tornadoes in Petroleum County from 1962 to 2020, the strongest rated F2, with 0 deaths and 0 injuries recorded in the county. That is 15th of 56 Montana counties by days with tornadoes per 1,000 square miles since 1950. A tornado that crossed a county line is counted in each county it touched, with the length of its path inside the county.
Counted as whole tornadoes rather than county records, the Storm Prediction Center's database holds 8 tornadoes whose track touched Petroleum County since 1950 (NOAA's county records number 8, the same count); along their whole tracks they killed 0 people.
Map of the strongest tornado tracks in Montana.
Every tornado record filed for Petroleum County (8)
| Date | Place | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2020-07-07 | Winnett, Petroleum County | EF0 0.14 mi x 20 yd | 0 | 0 | – |
| 2020-07-07 | Dry Blood Creek Raws, Petroleum County | EF0 0.15 mi x 50 yd | 0 | 0 | – |
| 2005-06-28 | Winnett, Petroleum County | F0 2 mi x 10 yd | 0 | 0 | – |
| 2002-07-08 | Winnett, Petroleum County | F0 2 mi x 50 yd | 0 | 0 | – |
| 2002-06-22 | Winnett, Petroleum County | F0 0.1 mi x 50 yd | 0 | 0 | – |
| 1992-07-23 | Petroleum County | F0 0.1 mi x 10 yd | 0 | 0 | – |
| 1978-07-03 | Petroleum County | 0 | 0 | – | |
| 1962-08-07 | Petroleum County | F2 2 mi x 10 yd | 0 | 0 | $3K step |
A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.
Source: NOAA NCEI Storm Events Database, tornado records by county (path length in the county, maximum width); ratings as published: F scale before February 1, 2007, EF scale after. Whole-track figures: NOAA Storm Prediction Center tornado database (1950-2025). SPC severe weather database.
When was the last damaging storm in Petroleum County?
The most recent record with damage, injuries or deaths is the June 9, 2016 hail ($615,000 in damage in 2025 dollars).
Petroleum County Emergency Manager reported hen egg sized hail, wind gusts to 50 mph, trees downed, roofs and siding damaged, and power outages. Event also resulted in 1 injury: A man was blown off his horse and later transported with injuries to Billings, MT.
National Weather Service event narrative, NOAA Storm Events Database (search the full record, event 642465)
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2026-06-01 | DroughtPetroleum County · forecast zone Petroleum | 0 | 0 | – | |
| 2026-05-26 | DroughtPetroleum County · forecast zone Petroleum | 0 | 0 | – | |
| 2026-05-13 | Thunderstorm WindWinnett, Petroleum County | 53 kt wind | 0 | 0 | – |
| 2026-05-13 | Thunderstorm WindDry Blood Creek Raws, Petroleum County | 59 kt wind | 0 | 0 | – |
| 2026-05-13 | Thunderstorm WindWinnett, Petroleum County | 50 kt wind | 0 | 0 | – |
| 2026-05-13 | Thunderstorm WindTeigen, Petroleum County | 53 kt wind | 0 | 0 | – |
| 2026-05-13 | Thunderstorm WindTeigen, Petroleum County | 60 kt wind | 0 | 0 | – |
| 2026-05-13 | Thunderstorm WindDry Blood Creek Raws, Petroleum County | 51 kt wind | 0 | 0 | – |
| 2026-05-13 | Thunderstorm WindTeigen, Petroleum County | 63 kt wind | 0 | 0 | – |
| 2026-05-13 | Thunderstorm WindTeigen, Petroleum County | 63 kt wind | 0 | 0 | – |
| 2026-04-11 | Thunderstorm WindWinnett, Petroleum County | 56 kt wind | 0 | 0 | – |
| 2026-03-17 | High WindPetroleum County · forecast zone Petroleum | 37 kt wind | 0 | 0 | – |
Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.
The deadliest and costliest records
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 1998-09-18 | LightningWinnett, Petroleum County One man died after lightning struck him and a friend while the two were bow hunting. The two were hunting between Crooked Creek and Barrel Springs when a thunderstorm moved overhead. The two took cover under a tree. Lightning struck the pair knocking both unconscious. When the one man awoke he tried to revive his ... | 1 | 1 | – |
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2014-08-23 | FloodWinnett, Petroleum County | 0 | 0 | $642K | |
| 2016-06-09 | HailWinnett, Petroleum County | 2.00 in hail | 0 | 0 | $615K |
| 1999-07-24 | Thunderstorm WindWinnett, Petroleum County | 0 | 0 | $35K |
Before 1993 NOAA filed damage by category, not amount, so the list above starts in 1993. The highest category filed here before then (entered as $3K, in the dollars of the day) holds: August 7, 1962 (tornado, Petroleum County).
Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.
Is it getting more frequent?
Records per decade for Petroleum County's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).
| Hazard | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020-26 |
|---|---|---|---|---|---|---|---|---|
| Hail | 0 | 1 | 1 | 0 | 16 | 47 | 33 | 17 |
| Severe thunderstorm wind | 0 | 0 | 0 | 1 | 6 | 33 | 12 | 28 |
| Winter storms | – | – | – | – | 7 | 21 | 29 | 9 |
| High wind and dust storms | – | – | – | – | 4 | 13 | 9 | 15 |
| Drought | – | – | – | – | 0 | 3 | 7 | 26 z |
| Floods | – | – | – | – | 1 | 4 | 16 | 3 |
Drought in the 2020-26: 26 records against 7 in the decade before, 26 of them forecast-zone records. Cells marked z rose mostly through zone records. The local National Weather Service office files these once per forecast zone, so a change in how it draws its zones or splits a storm into records moves this count as much as the weather does; read it beside the Petroleum County days with a record above.
Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).
What time of year?
79% of its hail reports since 1963 fell in June and July. The two busiest months are in violet.
The values, month by month
Jan 24 · Feb 25 · Mar 18 · Apr 20 · May 32 · Jun 73 · Jul 98 · Aug 41 · Sep 7 · Oct 13 · Nov 10 · Dec 28 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began.
Federal disaster declarations for Petroleum County
FEMA's register lists 12 declarations that include Petroleum County: 9 major disasters, 2 emergencies and one fire management assistance declaration. Most were for flood (4) and severe storm (3).
| Declared | Number | Type | Title |
|---|---|---|---|
| 2024-07-18 | DR-4801 | Severe Storm | Severe Winter Storm and Flooding |
| 2023-10-11 | DR-4745 | Flood | Flooding |
| 2020-03-31 | DR-4508 | Biological | Covid-19 Pandemic |
| 2020-03-13 | EM-3476 | Biological | Covid-19 |
| 2018-08-30 | DR-4388 | Flood | Flooding |
| 2017-07-27 | FM-5194 | Fire | Lodgepole Fire Complex |
| 2014-10-09 | DR-4198 | Severe Storm | Severe Storms, Straight-Line Winds, and Flooding |
| 2013-07-10 | DR-4127 | Flood | Flooding |
| 2011-06-17 | DR-1996 | Severe Storm | Severe Storms and Flooding |
| 2005-09-13 | EM-3253 | Hurricane | Hurricane Katrina Evacuation |
| 2000-08-30 | DR-1340 | Fire | Wildfires |
| 1986-03-15 | DR-761 | Flood | Heavy Rains, Landslides & Flooding |
Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.
FEMA's modeled risk for Petroleum County
FEMA's National Risk Index rates Petroleum County Very Low overall, with an expected annual loss of $1.6 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.
| Hazard | Risk rating | Expected annual loss | Modeled frequency |
|---|---|---|---|
| Lightning | Relatively Moderate | $538K | 29 a year (modeled) |
| Wildfire | Relatively Low | $142K | once in about 235 years (modeled) |
| Cold Wave | Relatively Low | $505K | 7.7 a year (modeled) |
| Drought | Very Low | $2K | 71 modeled event-days a year |
| Landslide | Very Low | $55 | about once a year (modeled) |
| Winter Weather | Very Low | $11K | 17 a year (modeled) |
| Hail | Very Low | $31K | 1.3 a year (modeled) |
| Heat Wave | Very Low | $7K | 2.9 modeled event-days a year |
Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.
Counties that share a border with Petroleum County
Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.
Next
- Tornadoes in MontanaEvery Montana tornado since 1950 and the counties with the most per square mile
- Hail in MontanaThe state's hail reports, by county, year and month
- The Montana recordEvery hazard in the state, its deadliest events and its federal declarations
- FEMA's risk rating for each hazard in Petroleum CountyThe hazard risk calculator: 18 hazards beside the county's record
- Download Petroleum County's FEMA declarations (CSV)12 rows: every declaration that named the county, for your own analysis