Powell County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Powell County: 0.
2. Weak tornadoes were under-recorded before Doppler radar coverage became national in the early 1990s, so earlier decades read low. Ratings use the Fujita scale before February 2007 and the Enhanced Fujita scale after.

Storm Prediction Center severe weather database, 1950 to 2025.

Every large fire

1. Large fires mapped by the Monitoring Trends in Burn Severity program since 1984: 1,000 acres or more in the West, 500 or more in the East. Prescribed burns are excluded. Acres here are the part of each perimeter inside this place.

Monitoring Trends in Burn Severity (USGS and U.S. Forest Service), 1984 to 2026.

Smoke overhead

1. A smoke day is a date on which a smoke plume traced by NOAA Hazard Mapping System analysts from satellite imagery covered this place's point (the county's population centre or the city centre). Counts here are of medium or heavy smoke. Since 2018 analysts have often drawn light smoke as one area over most of the continent, so light-smoke counts are not comparable from year to year. The plumes show smoke anywhere in the air above, not air quality at the ground, and smoke hidden by cloud is missed.

NOAA Hazard Mapping System smoke analysis, 2011 to 2026, retrieved October 30, 2026.

Claims by ZIP code

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).

OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026. NOAA Storm Events through 2026.

River crests

River gauges

1. Crests are the highest and the recent crests the National Weather Service lists for each river gauge in the county that has a flood stage, not every flood. Flood categories use each gauge's current flood stages; crests from before levees, dams or channel changes may not be comparable. Crests measured on an old datum are left out of the rankings.

NOAA National Water Prediction Service gauge records, retrieved October 30, 2026.

1. The Palmer Drought Severity Index is computed by NOAA each month from the county's average temperature and precipitation, relative to the county's own climate. Zero is normal; -3 or lower is severe drought and -4 or lower extreme drought. It describes the long-term balance of moisture, not water supply or crop losses.

NOAA NCEI nClimDiv county Palmer Drought Severity Index, 1895 to September 2026, issued October 6, 2026.

Every earthquake of magnitude 4 or more within 50 miles

1. Earthquakes of magnitude 2.5 or more in the USGS Comprehensive Catalog since 1900. Within 50 miles means the epicentre lies within 50 miles of the county boundary (or inside the county).
2. Small earthquakes were under-recorded before the modern seismic networks of the 1970s and are still missed in remote areas, so early decades read low. Magnitudes are as the catalogue reports them and mix scales (moment, local and body-wave).

USGS ANSS Comprehensive Earthquake Catalog, 1900 to present, retrieved October 30, 2026.

Mapped landslides

Mapped by USGS Conterminous (2), NASA (1).

1. Landslides mapped in the USGS compilation of landslide inventories across the United States (version 3.0, 2025), rated probable or better. The compilation joins inventories made by federal and state agencies for different purposes and areas, so the number mapped in a county reflects how closely it has been surveyed as much as how often its slopes fail. An area with few records may simply not have been mapped. Deaths are as recorded in the inventories; a slide listed in two inventories is counted once.

USGS Landslide Inventories across the United States, version 3.0, retrieved October 27, 2026.

More event types since 1996

Costliest events since 1996

1. Dec 29, 2004Heavy Snow, Butte / Pintlar Region$85,000
   National Weather Service narrative

   Heavy snow event across southwest Montana brought snow amounts ranging from 5 to 8 inches in the valleys to a foot over higher mountains. The city of Anaconda received a record breaking 5.9 inches for December 30th. The previous record was 5 inches set in 1977. The Montana Highway Patrol reported several severe accidents while at least 20 cars slid off roads from snow packed and icy roads. A truck driver totaled his $85,000 truck when he struck a vehicle in front of him who lost control and slowed down. His truck skidded sideways and rolled into a ditch.

2. Jun 19, 2018Flood$70,000
   National Weather Service narrative

   Cottonwood Creek overflowed its banks in downtown Deer Lodge on the afternoon of June 19. The excessive runoff flooded basements and surrounded numerous homes as water covered a whole city block. The Clark Street Bridge was over topped and remained closed for over a day. In addition, Tin Cup Joe Creek and Fred Burr Creek also experienced minor flooding.

3. Jul 17, 2013Thunderstorm Wind$30,000
   National Weather Service narrative

   A very large right-moving supercell tracked east-northeast from Goldcreek to north of Avon bringing with it large hail, severe winds and heavy rain. A rancher 5 miles north of Avon reported a totaled barn, several trees that were either uprooted or broken in half. One of those trees uprooted was a 24 cottonwood.

4. Jul 17, 2013Hail$13,000
   National Weather Service narrative

   A very large right-moving supercell unleashed up to ping pong sized hail that decimated a four to five foot tall hay crop. The hail covered the ground to a depth of 2 inches in spots. At least 10 windows were broken. Paint was chipped off from homes. Other damage included a greenhouse roof, vehicle windows and vegetation.

5. Jun 12, 2013Hail$6,000
   National Weather Service narrative

   A person from the public reported hail to the estimated size of ping pongs that caused damage to the roof to their house and extensive damage to their camper. The hail lasted for approximately 10 minutes.

6. Jul 17, 2013Hail$3,000
   National Weather Service narrative

   A very large right-moving supercell brought hail and wind damage to ranchers north of Avon. A rancher reported up to half dollar sized hail that brought considerable damage to their hay crop, and windows.

7. May 10, 2007Hail$2,000
   National Weather Service narrative

   A member of the public reported hail stones that that were between quarter and golfball in size. Damage to a couple of cars was observed.

8. May 22, 2023Thunderstorm Wind$2,000
   National Weather Service narrative

   A thunderstorm near Ovando showed a bowing structure, indicative of strong outflow winds. Velocity on the lowest radar tilt showed winds near 50 knots. Mid-altitude radial convergence was also present, adding confidence to severe wind gust potential. A report was received that the sign to the Ovando Store was blown over.

9. Jul 17, 2013Thunderstorm Wind$1,000
   National Weather Service narrative

   A very large supercell brought estimated 60 mph wind gusts that caused several trees to either uproot or break in half. Most of the trees fell in an easterly direction.

10. Aug 15, 2014Flash Flood$500
    National Weather Service narrative

    According to a spotter 1 mile west of Deer Lodge 0.80 of rain fell in a time span of 20 minutes. This rain resulted in street flooding in the town of Deer Lodge with water lapping doors of many businesses. The Powell County fair and rodeo were impacted by the flooding especially the fairgrounds exhibition center. Prisoners from the state prison were summoned to help setup sandbags to help mitigate the flooding.

1. Storm Events records before 1996 cover only tornadoes, thunderstorm wind and hail. Damage figures are as reported by the National Weather Service at the time, not adjusted for inflation.

NOAA NCEI Storm Events Database, 1950 to 2026, issued October 26, 2026.

All-time high

101°FJul 14, 2002

All-time low

−42°FDec 22, 1990

Warmest night

66°FAug 8, 2001

Coldest day

−26°FFeb 2, 1989

Wettest day

1.85 inJul 10, 1983

Snowiest day

12.0 in2 times, most recently Nov 12, 1959

Hottest year

2012mean 45.7°F

Coldest year

1964mean 39.0°F

Wettest year

197517.88 in

Driest year

20246.12 in

Snowiest season

73.9 in1966-67

Station Boulder (USC00241008), 4,904 ft elevation, 34.3 miles from the population centre. Daily records from 1880 to October 20, 2026; 86.5% of days in the last 30 years are complete. Records at a single station can differ from a city’s official threaded record, which may combine several stations.

NOAA NCEI Global Historical Climatology Network Daily.

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).

OpenFEMA Disaster Declarations Summaries, retrieved October 30, 2026. Statewide declarations are not listed.

Neighbouring counties

• Tornadoes NOAA Storm Prediction Center severe weather database, through 2025.
• Tropical cyclones NOAA National Hurricane Center HURDAT2 (Atlantic; Northeast and Central Pacific), through 2025.
• Wildfire USGS/USFS Monitoring Trends in Burn Severity, through 2026.
• Storm events NOAA NCEI Storm Events Database, through 2026.
• Flood insurance OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026.
• Declarations OpenFEMA Disaster Declarations Summaries v2, retrieved October 30, 2026.
• Weather records NOAA NCEI Global Historical Climatology Network Daily, station USC00241008.
• River crests NOAA National Weather Service, National Water Prediction Service river gauges, retrieved October 30, 2026.
• Drought NOAA NCEI nClimDiv county Palmer Drought Severity Index, through September 2026.
• Smoke NOAA NESDIS Hazard Mapping System smoke analysis, retrieved October 30, 2026.
• Landslides USGS Landslide Inventories across the United States, version 3.0 (2025).
• Earthquakes USGS ANSS Comprehensive Earthquake Catalog (ComCat), retrieved October 30, 2026.

Joins, thresholds and known limits are set out in the methodology. Found an error? Report it. Page built October 30, 2026.