Hancock County

Every recorded tornado

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

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.

Mapped landslides

Mapped by NASA (1).

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. Apr 8, 1999Tornado$15.0 million
   National Weather Service narrative

   A tornado developed just west of Warsaw in Hancock County and produced F2 damage to homes in the south part of the community. 2 homes were destroyed while another 30 structures suffered damage, including the high school track and football field and fairgrounds. Trees and branches were blown down in many parts of town.The tornado moved northeast into Hamilton where F3 damage occurred. The tornado destroyed or damaged 144 homes and businesses amounting to 10 million dollars in total damage. 4 people suffered minor injuries. The KHQA-TV tower and KOKX radio tower were destroyed. Governor George Ryan declared Hancock County a state disaster area. The tornado weakened and lifted just…

2. Jul 18, 2003Thunderstorm Wind$3.5 million
   National Weather Service narrative

   A bow echo raced across Southeast Iowa and West Central Illinois around and just after dawn. Numerous trees and power lines were downed as well as substantial crop damage. In Keokuk, Iowa, trees 3 to 4 feet in diameter were downed while in Nauvoo, Illinois, a 160,000 bushel grain bin along the river was crushed. In Camp Eastman north of Hamilton, 299 boy scouts and adults were camping. A tree limb fell on one tent and injured a boy scout. In the pre-dawn hours ahead of the bow echo, scattered severe storms developed in West Central Illinois producing hail and high winds.

3. May 21, 2003Flood, Hancock$1.0 million
   National Weather Service narrative

   A pattern change at the end of April brought a series of heavy rain producing systems to Eastern Iowa and Northern Illinois over the first 10 days of the month. Area rivers responded with the Iowa River going above flood stage starting on the 10th. The Cedar and Wapsipinicon Rivers followed by going above flood stage around the 15th. The Mississippi River also went above flood stage, beginning around the 20th. Most tributaries went below flood stage around the 20th, and most locations on the Mississippi that were above flood stage went below by the 28th.Most of the flooding was minor. One location-the Mississippi River at Gladstone Dam 18-experienced moderate flooding. Most…

4. Apr 30, 1997Tornado$400,000
   National Weather Service narrative

   A tornado tracked nearly three miles across mostly open farm land but still managed to strike five farms destroying several outbuildings and over 20 power poles. As the storm neared Warsaw, Illinois, nearly 50 homes sustained damage to windows from downed trees and flying debris. One home was damaged when a large 130 year old Oak tree toppled over. The tree destroyed the porch, carport, and the two family vehicles. Most disturbing, was that the tree crashed into the home and blocked the stairs to the basement just as the family attempted to take cover from the tornado. The family was unharmed.

5. May 10, 2003Tornado$400,000
   National Weather Service narrative

   Tornado developed in Adams County (WFO LSX) and moved northeast, entering Hancock county 1.2 miles southeast of Tioga at 1749 CST. The tornado moved in a northeast direction for 10.7 miles, passing 2.5 miles south of Basco where F2 damage was noted, and then turned slightly right. The tornado continued northeast for 17.7 miles, passing 1.2 miles south of Bentley and exited into McDonough County 3.9 miles SE of Fountain Green at 1830 CST. Most damage along the path in Hancock County was F0 and F1. The tornado was on the ground for a total of 28.4 miles in Hancock County.

6. Apr 30, 1997Tornado$400,000
   National Weather Service narrative

   A tornado tracked nearly three miles across mostly open farm land but still managed to strike five farms destroying several outbuildings and over 20 power poles. As the storm neared Warsaw, Illinois, nearly 50 homes sustained damage to windows from downed trees and flying debris. One home was damaged when a large 130 year old Oak tree toppled over. The tree destroyed the porch, carport, and the two family vehicles. Most disturbing, was that the tree crashed into the home and blocked the stairs to the basement just as the family attempted to take cover from the tornado. The family was unharmed.

7. Apr 30, 1997Tornado$400,000
   National Weather Service narrative

   A tornado tracked nearly three miles across mostly open farm land but still managed to strike five farms destroying several outbuildings and over 20 power poles. As the storm neared Warsaw, Illinois, nearly 50 homes sustained damage to windows from downed trees and flying debris. One home was damaged when a large 130 year old Oak tree toppled over. The tree destroyed the porch, carport, and the two family vehicles. Most disturbing, was that the tree crashed into the home and blocked the stairs to the basement just as the family attempted to take cover from the tornado. The family was unharmed.

8. Jun 27, 2011Thunderstorm Wind$250,000
   National Weather Service narrative

   Wind gusts in excess of 70 mph blew down several trees and large limbs in Bentley, IL around 145 am CDT June 27. Some roads were blocked by the tree debris. In addition, some buildings and homes were damaged and a new Morton building on the north side of Bentley was strewn across the freeway. Some of the trees and limbs fell onto a few homes.

9. Jun 27, 2011Thunderstorm Wind$250,000
   National Weather Service narrative

   Wind gusts estimated to be 60 to 80 mph downed several trees and large limbs across much of Hamilton, IL around 130 am CDT June 27. A home on North 19th Street sustained roof damage and a power pole was blown down in the front yard.

10. May 13, 2010Flood$250,000
    National Weather Service narrative

    Heavy rains during the second week of May resulted in the La Moine River at Colmar going above the moderate flood stage level of 22 feet on May 13 around 10 pm. It crested around 23.4 feet around 1 am May 15. It fell below the moderate flood stage level around 3 pm May 16.

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, 9.3 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.