Powder River County, Montana

What hazards hit Powder River County most?

The most frequent records are hail reports: 377 since 1957. 77% of its hail reports since 1957 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.

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 Powder River County had?

NOAA records 18 tornadoes in Powder River County from 1954 to 2014, the strongest rated EF2, with 0 deaths and 1 injury recorded in the county. That is 12th 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 18 tornadoes whose track touched Powder River County since 1950 (NOAA's county records number 18, the same count); along their whole tracks they killed 0 people.

Map of the strongest tornado tracks in Montana.

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 Powder River County?

The most recent record with damage, injuries or deaths is the August 5, 2025 flash flood ($2,000 in damage in 2025 dollars).

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

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: 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 Powder River 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).

Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).

What time of year?

77% of its hail reports since 1957 fell in June and July. The two busiest months are in violet.

Source: NOAA NCEI Storm Events Database, records by the month they began.

Federal disaster declarations for Powder River County

FEMA's register lists 12 declarations that include Powder River County: 8 major disasters, 2 emergencies and 2 fire management assistance declarations. Most were for fire (4) and biological (2).

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.

How many floods has Powder River County had?

NOAA's Storm Events Database holds 32 flood or flash flood records for Powder River County from 1999 to 2025, on 26 days, with 0 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Powder River County ranks 2477th of 2,942 U.S. counties.

The National Flood Insurance Program has paid $25,000 on 7 claims filed in Powder River County; the most in one year was 6 in 1978. Claims count insured losses only: uninsured flood damage is not in this file.

Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.

FEMA's modeled risk for Powder River County

FEMA's National Risk Index rates Powder River County Very Low overall, with an expected annual loss of $3.4 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.

Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.

Counties that share a border with Powder River County

1. Campbell County, WY 1,488
2. Crook County, WY 1,309
3. Rosebud County 832
4. Sheridan County, WY 815
5. Big Horn County 787
6. Powder River County 703
7. Custer County 686
8. Carter County 627

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 Powder River CountyThe hazard risk calculator: 18 hazards beside the county's record
• Download Powder River County's FEMA declarations (CSV)12 rows: every declaration that named the county, for your own analysis