Johnson County

Every recorded tornado

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

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 WY WSGS (597).

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. Aug 21, 2024Wildfire, Northeast Johnson County$12.5 million
   National Weather Service narrative

   The House Draw fire was sparked by by a lightning strike on the afternoon of August 21. Wind gusting to 40 mph spread the fire rapidly to the north and south of the ignition point, eventually consuming around 175000 acres before being mostly contained by August 30. At the height of the fire, Interstate 90 was closed for several hours to the east of Buffalo. Although no homes were lost in the fire, damage was extensive to ranch infrastructure with around 600 miles of fence burned along with the loss of storage and water tanks, outbuildings, feed., and equipment. Losses on private land alone were estimated by an unnamed source in the Green River Star local newspaper to be 25 million…

2. Aug 21, 2024Wildfire, Southeast Johnson County$12.5 million
   National Weather Service narrative

   The House Draw fire was sparked by by a lightning strike on the afternoon of August 21. Wind gusting to 40 mph spread the fire rapidly to the north and south of the ignition point, eventually consuming around 175000 acres before being mostly contained by August 30. At the height of the fire, Interstate 90 was closed for several hours to the east of Buffalo. Although no homes were lost in the fire, damage was extensive to ranch infrastructure with around 600 miles of fence burned along with the loss of storage and water tanks, outbuildings, feed., and equipment. Losses on private land alone were estimated by an unnamed source in the Green River Star local newspaper to be 25 million…

3. Jun 3, 2015Flash Flood$1.5 million
   National Weather Service narrative

   The last in a series of thunderstorms on Wednesday, June 3, brought very heavy rain to Buffalo and the surrounding area. The ASOS at Johnson County Airport measured 0.98 inches of rain in less than 25 minutes as the storm moved north and then stalled over Buffalo. The ASOS recorded a grand total of 1.26 inches in less than one hour. Saturated soils were unable to absorb the rain which quickly ran through the streets of Buffalo and filled area creeks. Five Buffalo homes were declared destroyed, and the senior center and BLM office sustained flood damage. Some reports indicated water four feet deep in low-lying areas. The water was running fast enough to lift and carry the top layer…

4. Aug 26, 2002Flash Flood$459,000
   National Weather Service narrative

   A stationary thunderstorm brought flash flooding and an estimated 3 inches of rain to Kaycee. Most of the rain fell between midnight and 4 AM MDT. The flooding did damage to 19 trailers and 22 houses. In addition, there was damage to 12 businesses, the post office, the conservation district office and telephone company. The force of the water along the Middle Fork of the Powder River resulted in a hotel being broken into three pieces, with one piece carried 75 yards, and two pieces deposited a few hundred yards away on the opposite side of the Middle Fork of The Powder River. By 715 AM MDT, the Middle Fork of the Powder River was out of its banks and 4 feet of water was reported…

5. Feb 18, 2016High Wind, Northeast Johnson County$250,000
   National Weather Service narrative

   Very strong wind gusts occurred across northern Johnson County. Some of these included 81 mph along I-90 north of Buffalo and 71 mph at the airport in Buffalo. Three light poles, several trees, and a baseball field backstop were blown down by the wind in Buffalo. There were numerous reports of shingle and roof damage around town.

6. Apr 18, 2011Debris Flow, Bighorn Mountains West$237,000
   National Weather Service narrative

   A rockslide on US Highway 14A east of Lovell in the Bighorn Mountains deposited at least 7,500 cubic yards of rock on the roadway. The slide occurred near milepost 73.4 and was witnessed and recorded by at least one person. The slide along with record snowpack kept the road closed beyond its typical Memorial Day opening. The cost of rock removal and road repair exceeded $200,000.

7. Jun 10, 2011Debris Flow, Bighorn Mountains West$165,000
   National Weather Service narrative

   The melting of record snowpack combined with heavy rain to saturate soils in the western Bighorn Mountains. Land below a section of U.S. Highway 14 above Shell Falls gave way near milepost 31.5 making travel on the highway unsafe. The slide, which measured at least 100 feet long, closed the highway for about three weeks.

8. Mar 28, 2007Blizzard, Northeast Johnson County$130,000
   National Weather Service narrative

   A slow-moving low pressure system produced widespread heavy snow and gusty wind crippling much of central Wyoming. Strong southerly pre-frontal wind gusts of around 60 mph were common ahead of the storm. Blizzard conditions were reported from Buffalo south to Casper as strong northeast upslope flow developed as the storm progressed east. Frequent reports of sustained wind of 35 mph with gusts to around 50 mph were received. The peak wind gust at Buffalo, one of the hardest hit areas, was 64 mph.|Impressive snowfall was received in conjunction with the prolonged period of upslope flow. Snowfall amounts of three to five feet were common in the Bighorn and Wind River Mountains, and…

9. Sep 1, 2007Wildfire, Bighorn Mountains West$100,000
   National Weather Service narrative

   The Bone Creek Wildfire that began on Monday, August 13 continued until Saturday, September 15. The fire scorched approximately 13,670 acres of forest, almost all of which resided within the borders of Big Horn County. The passage of a cold front shortly after midnight on Wednesday, September 5 shifted winds to the north allowing the blaze to jump U.S. Highway 14 west of Shell Falls. Six-tenths of a mile of guardrail burned along the highway which was closed for most of September 5 and 6. Firefighting costs were estimated at $2.8 million. No structures were burned in the blaze. More information about the origins of this wildfire are contained in the August 2007 Storm Data publication.

10. Aug 22, 2006Wildfire, Southeast Johnson County$65,000
    National Weather Service narrative

    Lightning caused the ignition of the Outlaw 2 wildfire approximately 20 miles southwest of Kaycee on Tuesday, August 22. The fire occurred near a famed area called Hole-in-the-Wall. The fire spread rapidly on Wednesday, August 23, growing from an estimated 300 acres on Tuesday to approximately 10,000 acres by midday Thursday, August 24. An estimated 12,270 acres were destroyed by the fire. One outbuilding and a restored historic cabin dating to early Wyoming history in the 19th century were consumed by the fire. The cost of the firefighting efforts reached $800,000.

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

105°FJul 13, 2005

All-time low

−34°FDec 22, 1990

Warmest night

85°FJul 8, 2002

Coldest day

−20°FFeb 3, 1989

Wettest day

2.62 inJun 25, 1969

Snowiest day

20.0 inJan 25, 1978

Hottest year

1999mean 50.7°F

Coldest year

1985mean 44.6°F

Wettest year

196718.83 in

Driest year

20127.68 in

Snowiest season

101.5 in1977-78

Station Tensleep 4NE (USC00488852), 4,748 ft elevation, 37.3 miles from the population centre. Daily records from 1964 to October 21, 2026; 91.9% 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 USC00488852.
• 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.