Riverton

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond this area.
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.

Flood insurance figures are for Fremont County, the county that contains Riverton.

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 in Fremont County, the county that contains Riverton.

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.

The drought index is for Fremont County, the county that contains Riverton.

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 city centre.
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

Landslides mapped in Fremont County.

Mapped by WY WSGS (2,699), NASA (4).

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. Jun 4, 2010Flood$12.0 million
   National Weather Service narrative

   Heavy snow and cool temperatures in May allowed snowpack to remain at unseasonably high levels across the southern end of the Wind River Range. With over 100 years of weather records, the month of May 2010 ranked as the third coldest at Riverton and tied as the fifth coldest at Lander, both neighboring basin towns. The first warm stretch of the early summer season came on June 2, 3, and 4, as basin temperatures finally climbed into the 70s. In turn, the large snowpack begin a rapid melt that quickly inundated area rivers and streams.||The Middle Fork of the Popo Agie River experienced a rapid rise on Friday afternoon, June 4. The rising waters caused flooding by late evening in…

2. Jun 23, 2023Hail$3.0 million
   National Weather Service narrative

   There were numerous reports of quarter to golf ball size hail in around around Riverton, with the largest hail stones reported on the east side of Riverton. Many vehicles sustained windshield and body damage from the hail. Dozens of homes on the east side of Riverton had roof shingle damage, with roof replacements occurring regularly over the next 4 months.

3. Jun 4, 2017Flood$2.0 million
   National Weather Service narrative

   Abnormally large snowpack melted across the mountains of western and central Wyoming and caused the Wind River to Flood. At the Gauge at Riverton, the river crested above 12 feet, a new record. Along the Riverton Irrigation Canal, the water got high enough to flow directly into the canal, threatening the city of Riverton with flooding. The canal had to be breached to prevent the flooding. As a result, many farmers along the canal were left without irrigation water into July. The repairs to the canal cost around an estimated $2 million dollars. In addition, there was extensive flooding of agricultural land along the Wind River to it's confluence with the Little Wind River.

4. May 7, 2016Flood$1.2 million
   National Weather Service narrative

   Widespread heavy rain of 2.50 to 4.50 fell in a broad swath across Fremont County during a 48-hour period from Friday evening, May 6, through Sunday evening, May 8. There was a peak rainfall amount of 6.88��� at a rain gauge about 6 miles west of Fort Washakie on the Little Wind River. The heavy rain fell over the lower elevations of the Wind River Basin and in the lower foothills of the Wind River Range.||The heaviest rainfall occurred between 1900MST Friday, May 6, and 1700MST Saturday, May 7. The rain gauge at Lander Hunt Field reported 3.82��� in this 22-hour period, with 1.12��� falling between 0800MST and 1100MST Saturday. The heavy rainfall contributed to…

5. Sep 18, 2004Wildfire, Wind River Basin$1.0 million
   National Weather Service narrative

   A human caused fire was started near Goes In Lodge Road on the Wind River Indian Reservation south of Riverton during the afternoon. The fire threatened urban areas on the south side of Riverton by late afternoon. The fire was fueled by dry southwesterly wind that gusted between 30 and 35 mph at times. A total of nine people were treated for minor injuries and smoke inhalation. The fire claimed 300 acres, four campers, 33 vehicles on a used car lot, and a mobile home used for storage. Damage totaled around one million dollars before the fire was extinguished.

6. Apr 10, 2006Wildfire, Lander Foothills$1.0 million
   National Weather Service narrative

   A prescribed fire originally lit on April 9th burned out of control on April 10th, destroying four summer cabins/homes and a pick-up camper in the Homestead Park #2 subdivision located eight miles southwest of Lander. The escaped fire burned 188 acres, of which 123 were on the Shoshone National Forest, five on BLM land, and 60 on private land. The estimated cost of fighting the fire was 333 thousand dollars. Combined with the estimated value of the four structures, the total cost of the wildfire was estimated at one million dollars.

7. Jul 4, 2009Flash Flood$500,000
   National Weather Service narrative

   Rainfall estimated at 1 to 2.5 inches fell in about 30 minutes along Gas Hills Road. WYDOT engineers reported 500 feet of shoulder was eroded from the road due to running water near mile marker 6.5. Two culverts in the area could not handle the extreme volume of water. Approximately three to four feet of the shoulder and road surface was swept away leaving a vertical drop of 12 to 14 feet. Witnesses said three feet of water was above the road surface along a quarter-mile stretch of the road for several hours.

8. Apr 17, 2005Wildfire, Wind River Basin$500,000
   National Weather Service narrative

   A human caused fire was started west of Fort Washakie during the afternoon. The fire became out of control and threatened urban areas of Fort Washakie resulting in the evacuation of all 250 residents. The fire was fueled by dry southwest winds that gusted between 20 and 30 mph at times. One firefighter suffered minor injuries fighting the fire. The fire consumed 156.39 acres of land on either side of the Little Wind River and an abandoned historic building in Fort Washakie.

9. Sep 26, 2013Winter Storm, Wind River Basin$500,000
   National Weather Service narrative

   Rain turned to snow during the evening across the Wind River Basin and continued into the following morning. Snowfall amounts ranged from 3 inches near Shoshoni to 8 inches northwest of Riverton. The heavy, wet snow fell on trees still with full foliage and caused many limbs to break and some entire trees to fall. As a result many streets were blocked and there were widespread power outages.

10. Mar 16, 1999High Wind, Lander Foothills$500,000
    National Weather Service narrative

    Official gust to 84 mph at the Lander airport; unofficial gusts to 141 mph and 107 mph in the foothills west of Lander. Considerable damage to trees, roofs, and automobiles in Lander and Ft. Washakie. Property damage amount is estimated. Gusts to 70 mph in the Casper area.

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

106°FJul 13, 2026

All-time low

−46°F5 times, most recently Dec 23, 1983

Warmest night

71°FJul 26, 2011

Coldest day

−23°FDec 22, 1990

Wettest day

3.53 inMay 8, 1921

Snowiest day

21.8 inNov 24, 2023

Hottest year

2012mean 48.6°F

Coldest year

1993mean 39.5°F

Wettest year

191220.58 in

Driest year

19882.77 in

Snowiest season

94.7 in2022-23

Station Riverton (USC00487760), 4,955 ft elevation, 0.5 miles from the city centre. Daily records from 1907 to October 27, 2026; 92.3% 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.

Declarations for Fremont County.

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.

• 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 USC00487760.
• 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.