Clark County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Clark County: 2.
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.

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 MO DNR (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. May 8, 2003Hail$1.0 million
   National Weather Service narrative

   The first of 3 severe weather events occurred across Northeast Missouri, Eastern Iowa, and the Northern third of Illinois. Supercell thunderstorms developed in the late afternoon and evening north of a warm front that was associated with a powerful spring storm system. Favorable moisture and shear profiles allowed the storms to produce large hail and heavy rain. In Fort Madison, Iowa it was reported to be the most hail seen since 1993 with a car dealership reporting damage to about 400 cars on its lot along with numerous cars and buildings. In the Burlington, Iowa area, the most severe damage from the hail was on the south side of the city. Three schools and a golf course were…

2. May 8, 2003Hail$1.0 million
   National Weather Service narrative

   The first of 3 severe weather events occurred across Northeast Missouri, Eastern Iowa, and the Northern third of Illinois. Supercell thunderstorms developed in the late afternoon and evening north of a warm front that was associated with a powerful spring storm system. Favorable moisture and shear profiles allowed the storms to produce large hail and heavy rain. In Fort Madison, Iowa it was reported to be the most hail seen since 1993 with a car dealership reporting damage to about 400 cars on its lot along with numerous cars and buildings. In the Burlington, Iowa area, the most severe damage from the hail was on the south side of the city. Three schools and a golf course were…

3. Jun 20, 2011Flood$500,000
   National Weather Service narrative

   Heavy rains during the second week of June caused the Fox River to flood Alexandria, MO during the third week of June. Much of the town was under flood waters.

4. Jun 4, 2010Flash Flood$500,000
   National Weather Service narrative

   Heavy rains resulted in flash flooding across much of Clark County during the evening of June 4. Water covered numerous roads across the county including Route 81 and Highway 136. Several streams and creeks overflowed their banks.

5. Sep 13, 2008Flood$500,000
   National Weather Service narrative

   The Fox River near Wayland, MO experienced major flooding from the evening of September 13 to the afternoon of September 15. It crested near 20.6 feet during the early morning hours of September 15. The major flood stage level is 20.0 feet.

6. May 13, 2010Flood$500,000
   National Weather Service narrative

   Heavy rains during the second week of May resulted in the Fox River at Wayland going above the moderate flood stage level of 18 feet on May 13 around 330 pm. It crested around 19.3 feet around 1 pm May 14. It fell below the moderate flood stage level around 330 am May 15.

7. May 10, 2003Tornado$250,000
   National Weather Service narrative

   Tornado developed northwest of Edina in Knox County (WFO LSX) and moved northeast through Scotland County and entered Clark County 2.3 miles WNW of Fairmont at 1657 CST. Tornado continued northeast for 10.7 miles, passing 2.2 miles South of Wyaconda and dissipated 1.2 miles South of Medill at 1708 CST. Tornado was rated F0 with a path length of 10.7 miles in Clark County.

8. Jul 20, 2010Flood$250,000
   National Weather Service narrative

   Heavy rains during the third week of July resulted in the Des Moines River at Wayland going above the moderate flood stage level of 18 feet around 240 pm CDT July 20. It crested around 19.4 feet around 7 am CDT July 21. It fell below the moderate flood stage level around 5 am July 22.

9. Jul 19, 2010Flood$250,000
   National Weather Service narrative

   Heavy rains during the third week of July resulted in the Des Moines River at St. Francisville going above the moderate flood stage level of 22 feet around 1045 am CDT July 19. It crested around 25.3 feet around 7 am CDT July 20. There was a secondary crest around 23.6 feet around 7 pm CDT July 25. It fell below the moderate flood stage level around 9 am CDT July 27.

10. Jun 22, 2010Flood$250,000
    National Weather Service narrative

    Heavy rains during the third week of June resulted in the Des Moines River at St. Francisville going above the moderate flood stage level of 22 feet on June 22 around 530 am. It crested around 22.8 feet around 7 am June 22. It fell below the moderate flood stage level around 930 pm June 22.

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 15, 1936

All-time low

−22°FJan 10, 1982

Warmest night

87°F3 times, most recently Jul 9, 1987

Coldest day

−10°F2 times, most recently Feb 3, 1996

Wettest day

5.38 inAug 23, 2001

Snowiest day

10.5 inFeb 19, 1908

Hottest year

1987mean 56.9°F

Coldest year

1996mean 48.0°F

Wettest year

201056.82 in

Driest year

198818.23 in

Snowiest season

45.5 in1959-60

Station Keokuk L&d 19 (USC00134381), 522 ft elevation, 17.6 miles from the population centre. Daily records from 1933 to October 27, 2026; 98.8% 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 USC00134381.
• 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.