Natrona County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Natrona 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 WY WSGS (690).

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. Jul 3, 2009Flash Flood$5.0 million
   National Weather Service narrative

   A vicious thunderstorm struck the city of Casper between about 1715 and 1800MST at the start of the July 4th holiday weekend. Extreme rainfall rates falling on the urbanized landscape produced flash flooding throughout Casper, with the most extensive inundation centered around the intersection of Poplar and Collins streets.||Nearly one inch of rain fell in 21 minutes at the Natrona County International Airport northwest of the city. A precipitation gauge along the North Platte River in Casper reported 1.79 inches of rain in 30 minutes. Final tallies around town showed rainfall from around one inch up to a high of about 2.25 inches occurred within about a 35 minute time…

2. Oct 11, 2015Wildfire, Natrona County Lower Elevations$5.0 million
   National Weather Service narrative

   The Cole Creek Wildfire spread rapidly in windy, dry, and warm conditions on Sunday, October 11. The fire carried quickly through grassy fuels and caused the evacuation of several neighborhoods in the vicinity of Coal Creek Road northeast of Casper. No human lives were lost, but the wildfire did eventually consume numerous homes, outbuildings, vehicles, pets, and livestock.||The fire began around 1720MST on Saturday, October 10, in a wood chip pile at the Casper Regional Landfill north of Casper. On Sunday, gusty southwest wind steadily increased through the morning hours. Sustained wind of 30 to 40 mph and gusts of 45 to 50 mph were recorded by 0800MST at nearby Casper-Natrona…

3. Sep 9, 2012Wildfire, Casper Mountain$4.0 million
   National Weather Service narrative

   The Sheep Herder Hill Fire started on the southeast side of Casper Mountain off of Circle Drive on Sunday, September 9. The wildfire was spread rapidly east and northeast by high temperatures, strong wind, and dry fuels. The afternoon that the blaze erupted was characterized by southwest wind gusting 30 to 40 mph and relative humidity of less than 10%. Structural damage from the fires began the first evening with at least 6 structures destroyed. By the following morning the fire had already consumed about 5,000 acres. The rapid rate of spread continued on September 10 with wind gusts again topping 30 mph for 7 hours during the afternoon and evening. A cold front swept across the…

4. Oct 3, 2013Winter Storm, Natrona County Lower Elevations$3.0 million
   National Weather Service narrative

   Most areas of Natrona County received over a foot of snow including 16.2 inches at the Casper Airport and up to 22 inches in the foothill areas of Casper Mountain. The heavy, wet snow fell on trees that still had full foliage and caused branches and in some cases whole trees to fall. Many of these landed on power lines and caused widespread power outages. Around 14,000 customers were without power at the peak of the storm.

5. Jun 15, 2023Flash Flood$2.9 million
   National Weather Service narrative

   Rainfall reports for the 24 hour period including the flash flood event ranged from 1.30 to 3.47 inches. Flooding was initially reported in downtown Casper where cars where were reported as floating in flowing water. On the south side of Casper, a house was reported as shifted off of its foundation. Interstate 25 became flooded at the peak of the event, and was closed for until well after rainfall ended. Low-lying tunnels on the south side of Casper had as much as 5 feet of water in them at the height of the storm. Damage values have been updated as of Oct 2023 and are from the FEMA presidential disaster declaration, FEMA-4739-DR-WY. No injuries or fatalities were reported to the NWS.

6. Aug 12, 2006Wildfire, Natrona County Lower Elevations$1.2 million
   National Weather Service narrative

   The Jackson Canyon Wildfire began shortly before noon on Saturday, August 12. The fire started in Jackson Canyon near Coal Mountain from a lightning strike. By Monday, August 14 the fire had spread to Casper Mountain and necessitated the evacuation of numerous homes and the closure of roads on the mountain. The fire spread to the north-facing slope of Casper Mountain early Tuesday, August 15 and threatened several subdivisions at the foot of the mountain. Additional evacuations and road closures occurred as the fire encroached on southwest Casper. The fire raged Wednesday and Thursday, August 16 and 17, as gusty southwest wind and low relative humidity were prevalent. A cold…

7. Aug 2, 2007Flash Flood$500,000
   National Weather Service narrative

   Thunderstorms producing heavy rain formed northwest of Casper during the late evening. The storms tracked southeast along and south of U.S. Highway 20/26 over areas that had been hard hit by heavy rain over the previous two weeks. Natrona County Emergency Management officials reported flooding at the intersection of Poison Spider and 12 Mile roads at 8:57 p.m. Flooding along Poison Spider Road continued to increase through 10:00 p.m. with additional reports of ditches overflowing in and around Mills. Heavy rainfall of nearly one inch fell in less than 30 minutes at the Natrona County International Airport causing flooding. The Poison Spider Elementary School was flooded for the…

8. Jul 25, 2005Flash Flood$500,000
   National Weather Service narrative

   A line of strong thunderstorms moved west to east across Natrona County between 4:30 p.m. and 6:30 p.m. These storms originated over the Bighorn mountains of Wyoming and rapidly intensified near the Natrona County International Airport, 6 miles west of Casper, where a 54 kt wind gust was reported. The airport received nearly an inch of rain between 5:35 p.m. and 6:05 p.m. The storms hit the Casper area between 5:50 p.m. and 6:20 p.m. with similar strong outflow winds followed by reports of up to 1.44 inches of rainfall over this 30 minute period. The brief torrent of rain produced flooding on the north side of downtown Casper, shutting down portions of Interstate 25. Portions of…

9. Jul 25, 2007Flash Flood$300,000
   National Weather Service narrative

   Rainfall estimated by radar to be three inches or more fell in a swath from Emigrant Gap to Bar Nunn. The heavy rain caused flash flooding along Poison Spider Road and other nearby roads as culverts could not handle the large volume of water. Portions of a ranch along Poison Spider Road were under several feet of water. A mobile home park south of Bar Nunn was flooded as water flowed from surrounding higher terrain. The lower floor of the rural Poison Spider Elementary School sustained flood damage as the water poured in through several doorways.

10. 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.

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

104°F3 times, most recently Jul 29, 2006

All-time low

−42°FDec 22, 2022

Warmest night

74°FJul 18, 2006

Coldest day

−25°FFeb 3, 1989

Wettest day

2.22 inMay 17, 2000

Snowiest day

26.7 inApr 3, 2023

Hottest year

1994mean 49.2°F

Coldest year

1985mean 42.6°F

Wettest year

198220.48 in

Driest year

20205.79 in

Snowiest season

151.6 in1982-83

Station Casper-natrona County Airport (USW00024089), 5,319 ft elevation, 8.0 miles from the population centre. Daily records from 1948 to October 26, 2026; 99.9% 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 USW00024089.
• 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.