Millard County

Every recorded tornado

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

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.

Volcanoes within 100 miles

1. U.S. volcanoes within 100 miles, from the USGS Volcano Hazards Program. The threat category is the USGS 2018 National Volcanic Threat Assessment, which ranks volcanoes by how hazardous their past eruptions were and how many people and how much infrastructure lie near them. It is not a forecast of eruption.

USGS Volcano Hazards Program, retrieved October 30, 2026.

Mapped landslides

Mapped by UT GRC (218), USGS Conterminous (5).

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 18, 2021Flood$1.0 million
   National Weather Service narrative

   Widespread basement flooding occurred in and around Delta. An observer reported a 2-day rainfall total of 5.83 inches.

2. Apr 14, 2015Wildfire, Central Mountains$350,000
   National Weather Service narrative

   The Quakie Haven Fire began near Fish Lake on the afternoon of April 14, and grew quickly due to strong winds. The fire destroyed two summer cabins and damaged several outbuildings and other structures in the Sleepy Hollow area, but fire crews were able to keep the blaze away from other cabins in the area. The fire also forced the temporary closure of portions of State Route 25. Suppression efforts continued for more than a week after the blaze was ignited, but the fire was effectively under control and was no longer threatening structures beginning on the evening of the 14th of April.

3. Jul 25, 2021Dust Storm, Eastern Juab/Millard Counties$300,000
   National Weather Service narrative

   Thunderstorm outflow winds generated blowing dust with near zero visibility along Interstate 15 near milepost 152 south of Fillmore. This resulted in a multi vehicle pileup with at least 22 vehicles involved, 8 fatalities, and 10 injuries. The nearest mesonet site located 7 miles south of the crash site recorded a wind gust to 32 mph around the time of the crash, at approximately 430 PM MDT.

4. Jul 1, 2012Wildfire, Central Mountains$250,000
   National Weather Service narrative

   The Clay Springs Fire began on July 27th east of Delta, Utah, and was human-caused. Clay Springs was the largest fire of the year in the state of Utah, burning a total of 107,846 acres before it was 100% contained on July 21st. The fire forced the evacuation of nearly 1,000 people, including the entire communities of Oak City and Fool Creek. Damages from the fire included one cabin that was destroyed, minor damage to a few other residences, 3 city storage structures destroyed, and dozens of power poles damaged. Two firefighters were injured by the blaze. In addition to physical damages, fire suppression cost a total of $6.6 million. Note that this event began in June, and monetary…

5. Sep 1, 2012Flash Flood$100,000
   National Weather Service narrative

   Heavy rain over the Clay Springs burn scar caused a debris flow on the afternoon of September 1st. Four homes in the Fools Creek area experienced flooded basements, and one yard was severely damaged. In addition, a single wide trailer in the same area was pushed off its foundation. Six to eight inches of mud and debris crossed Highway 125, causing some damage along the edges of the roadway.

6. Feb 17, 2026Winter Storm, Central Mountains$70,000
   National Weather Service narrative

   Several SNOTEL stations including Seely Creek, Upper Joes Valley, and Red Pine Ridge recorded from 0.9 to 1.5 inches of snow water equivalent, resulting in approximately 12 to 21 inches of snow. Some peak wind gust observations through the event include 84 mph at Signal Peak, 80 mph at Scipio Summit, and 76 mph at Bull Claim Hill. Multiple vehicle accidents and slide-offs were also reported along I-70.

7. Jan 5, 2026Winter Weather, Eastern Juab/Millard Counties$60,000
   National Weather Service narrative

   Utah Highway Patrol reported numerous traffic accidents on I-15 between approximately the Nephi exit and roughly two miles northward. The volume of accidents resulted in the southbound lanes of I-15 being closed and traffic being detoured through the city itself. The winter weather is assumed to be the likely cause of the incident.

8. Jul 5, 2011Flood$50,000
   National Weather Service narrative

   The Sevier River once again experienced flooding in the month of July, but this time it was areas of Millard County that received the worst of the damage. The access road between Highways 50 and 257 was closed due to water running over the roadway. Water from Sevier River also flowed over portions of Highways 6 and 50, but did not result in any damage or closures. Flooding occurred at various points on the Sevier River channel from Leamington through Lynndyl, in the Delta and Deseret areas, and all the way to Sevier Lake. A few different county roads and bridges were closed or damaged, including the Leamington Bridge in Leamington and the access road to the Gunnison Massacre…

9. Jul 17, 2023Thunderstorm Wind$36,000
   National Weather Service narrative

   Strong crosswinds associated with outflow from nearby showers and thunderstorms resulted in multiple overturned semitrailers on Interstate 15 at milepost 163. Around this time, the UTCIR mesonet sensor recorded a wind gust of 71 mph. Video from broadcast media showed a semitrailer rolling at speed, with subsequent articles indicating multiple semitrailers were rolled. Additionally, the video showed a substantial dust plume as a result of the strong winds.

10. May 31, 2023Thunderstorm Wind$30,000
    National Weather Service narrative

    An apparent dry microburst occurred as a result of thunderstorms moving through the area. Broadcast media subsequently shared photos of a severely damaged airplane hangar.

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

110°F2 times, most recently Jul 13, 2002

All-time low

−30°FDec 23, 1990

Warmest night

76°FJul 12, 2017

Coldest day

−1°FDec 23, 1998

Wettest day

4.39 inAug 18, 2021

Snowiest day

16.0 inMay 20, 1975

Hottest year

2025mean 54.7°F

Coldest year

1984mean 46.8°F

Wettest year

199813.44 in

Driest year

20202.16 in

Snowiest season

66.4 in1948-49

Station Delta (USW00023162), 4,620 ft elevation, 10.4 miles from the population centre. Daily records from 1938 to September 30, 2026; 91.0% 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 USW00023162.
• 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.
• Volcanoes USGS Volcano Hazards Program, U.S. volcanoes and 2018 threat assessment.
• 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.