Big Horn County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Big Horn 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.

More event types since 1996

Costliest events since 1996

1. May 21, 2011Flood$4.0 million
   National Weather Service narrative

   From May 21st and even continuing into the month of June, extensive severe flooding occurred across Big Horn County from the Little Bighorn and Bighorn Rivers, as well as creeks and streams. An Incident Command Center was set up in Crow Agency where the Crow Tribal Chairman declared a disaster. At the height of the flooding, the Big Horn County Sheriffs office is quoted as saying, there is water everywhere. Hundreds of people were evacuated as flooding affected every community on the Crow Reservation. Fifteen to twenty homes were heavily impacted by the flooding. Interstate 90 south of Hardin to the Wyoming State line was closed for five days (May 21-26). Water rescues were…

2. Apr 9, 2001Heavy Snow, Big Horn$1.2 million
   National Weather Service narrative

   Heavy, wet snow with 4 to 5 foot drifts in the Decker and Kirby area along highway 314.

3. Jul 5, 1998Hail$100,000
   National Weather Service narrative

   Baseball sized hail damaged numerous vehicles and broke several windows and yard lights.

4. Jul 23, 2000Thunderstorm Wind$10,000
   National Weather Service narrative

   Wind damage. Large tree downed. Roof damaged.

5. Jul 27, 2000Thunderstorm Wind$4,000
   National Weather Service narrative

   Roof damage at Decker with thunderstorm winds.

6. Jul 23, 2000Thunderstorm Wind$3,000
   National Weather Service narrative

   Wind damage with 60-70 mile per hour winds. Large trees downed.

7. Jul 23, 2000Thunderstorm Wind$3,000
   National Weather Service narrative

   Wind damage with 60 mph winds. Trees downed.

8. Jul 9, 2000Thunderstorm Wind$2,000
   National Weather Service narrative

   58 mph thunderstorm wind gust. Tree limbs down.

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

112°FJul 14, 2002

All-time low

−47°FDec 22, 1989

Warmest night

78°FAug 5, 2003

Coldest day

−20°FDec 30, 1968

Wettest day

3.17 inApr 4, 1955

Snowiest day

12.0 inFeb 20, 2011

Hottest year

2006mean 51.7°F

Coldest year

1951mean 42.2°F

Wettest year

202521.72 in

Driest year

19845.68 in

Snowiest season

74.6 in2017-18

Station Hardin (USC00243915), 2,880 ft elevation, 12.5 miles from the population centre. Daily records from 1948 to October 26, 2026; 95.4% 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 USC00243915.
• 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.
• 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.