Clay County

Every recorded tornado

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

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. Jun 21, 2024Flood$25.6 million
   National Weather Service narrative

   Rainfall amounts across Clay County from June 20-22 ranged from 3 to 7 inches. Farther north and upstream, up to 10 inches of rain fell across portions of northwest Iowa. This rainfall resulted in extensive overland flooding and record flooding along the Little Sioux and Ocheyedan Rivers. ||The city of Spencer experienced catastrophic flooding when waters from the Little Sioux and Ocheyedan Rivers overtopped the city's berm system. At peak flooding, approximately 383 people were rescued, leaving hundreds of residents displaced. Eighty homes had collapsed or caved-in foundations and roughly 2,100 structures of the 5,100 throughout the city were damaged by flood waters. Numerous…

2. Apr 10, 2013Winter Storm, Clay$10.0 million
   National Weather Service narrative

   A period of precipitation began with freezing rain quickly producing heavy ice accumulations, ranging up to between a quarter and half inch. The precipitation then changed to sleet and then snow, with sleet and snow accumulations reaching 2 to 4 inches. Many branches, limbs, whole trees, and power lines were downed by the weight of ice and accompanying wind, especially over the northern part of the county. Both urban areas and rural electric cooperatives suffered major power line damage. Trees and tree debris blocked many roads, and damaged several vehicles and homes. Major power outages were reported, affecting thousands of people. The winter precipitation made travel impossible…

3. Mar 13, 2019Flood$550,000
   National Weather Service narrative

   Flooding resulted in extensive damage to public infrastructure including numerous county and township roads, culverts, and some bridges.

4. Sep 8, 2005Hail$500,000
   National Weather Service narrative

   Large hail fell in an area around 20 miles long and 3 to 5 miles wide. The hail was quarter to golf ball size over most of the area but reached baseball size at Everly. The hail, driven by accompanying damaging winds, broke windows in buildings and vehicles, dented vehicles, and damaged roofs and siding on homes and other buildings. Besides Everly and Webb, the communities of Greenville and Rossie were also affected. The hail covered the ground over much of the area, and was blown into drifts as high as 3 feet. Corn and soybean crops were heavily damaged, with the greater damage to soybean crops. The amount of crop damage was not known.

5. May 21, 2004Hail$500,000
   National Weather Service narrative

   Large hail damaged vehicles, broke windows, and damaged roofs and siding. Crop damage was also extensive with over one hundred thousand acres of corn, bean, and other small grain crops affected during this storm and another hail storm in the area earlier in the day. The amount of crop damage was not known. Property damage was in addition to the damage from the earlier storm.

6. Sep 8, 2005Thunderstorm Wind$500,000
   National Weather Service narrative

   Thunderstorm winds caused widespread tree, power pole, and power line damage along a path around 20 miles long and roughly 5 miles wide. Numerous trees were blown down, some blocking roads, forcing law enforcement to close all roads leading to Everly. Damage to structures was also reported, including shingles blown off roofs, siding damaged, and several small outbuildings and other rural structures destroyed or heavily damaged. Power outages resulted in Everly and in several rural areas. Besides Everly and Webb, the communities of Greenville and Rossie were also affected. The winds also contributed to damage caused by accompanying large hail, and blew the hail into drifts. The…

7. Jun 18, 2014Flood$500,000
   National Weather Service narrative

   Persistent heavy rains caused moderate to major flooding of the Little Sioux River. Farmland, other lowlands including parks, and several roads near the river were flooded, including in the city of Spencer. Some homes were flooded, mainly in basements. The river crested at 5.18 feet above flood stage at Spencer on June 20th.

8. Jun 11, 2004Tornado$500,000
   National Weather Service narrative

   A tornado destroyed a hog barn, killing ten hogs, destroyed a greenhouse, destroyed a barn, outbuildings, a machine shed and a garage, and damaged several other farm structures including a horse barn. Several horses were injured. At least two houses were damaged, with windows blown out. Several vehicles were also damaged. Numerous power lines and trees were blown down. The tornado also damaged crops.

9. May 21, 2004Hail$500,000
   National Weather Service narrative

   Large hail caused widespread damage to vehicles, windows, and roofs. Crop damage was also extensive in the area with over one hundred thousand acres of corn, beans, and other small grain crops affected during this storm and another hail storm which occurred later in the day. The amount of crop damage was not known.

10. Apr 7, 2001High Wind, Clay$400,000
    National Weather Service narrative

    High winds caused widespread tree, sign, and roof damage. Other damage to structures, such as siding and windows, also occurred. The Spencer Livestock Sales facility was heavily damaged with fences blown down and the wall of one building blown down, although there were no reports of livestock lost.

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

113°FJul 17, 1936

All-time low

−38°FJan 12, 1912

Warmest night

80°F2 times, most recently Jul 6, 1936

Coldest day

−18°FFeb 8, 1899

Wettest day

5.01 inSep 7, 1964

Snowiest day

14.0 inMar 3, 1977

Hottest year

1931mean 52.0°F

Coldest year

1951mean 42.0°F

Wettest year

201645.78 in

Driest year

195814.41 in

Snowiest season

81.9 in1961-62

Station Spencer 1 N (USC00137844), 1,326 ft elevation, 2.7 miles from the population centre. Daily records from 1895 to October 25, 2026; 98.6% 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 USC00137844.
• 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.