Bon Homme County

Every recorded tornado

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

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.

More event types since 1996

Costliest events since 1996

1. Mar 13, 2019Flood$1.5 million
   National Weather Service narrative

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

2. Jun 21, 2024Flood$1.2 million
   National Weather Service narrative

   Rainfall amounts across Bon Homme County from June 20-22 ranged from 2 to 3 inches with an estimated 5 to 6 inches across the far northern portion of the county. Overland flooding ensued with additional major flooding along the James River.||One home experienced a partial basement collapse and 3 businesses received flood damage. ||During peak flooding on June 21, water was overflowing at least 60 roads county-wide with the worst impacts north of South Dakota Highway 46, including South Dakota Highway 25 and the intersection of South Dakota Highways 46 and 37. Water also overran South Dakota Highway 50 near the Bon Homme Golf Course. Preliminary damage assessments estimate loss to…

3. Sep 4, 2016Thunderstorm Wind$1.0 million
   National Weather Service narrative

   Thunderstorm winds destroyed about 6 houses, severely damaged several other houses and shops, destroyed or damaged several unattached garages, destroyed farm outbuildings and other farm structures, caused widespread tree damage, including numerous trees blown down, moved a large boat 25 yards from a parked position, damaging the boat, and damaged or destroyed outdoor furniture.

4. Nov 27, 2005Ice Storm, Bon Homme$1.0 million
   National Weather Service narrative

   Heavy freezing rain coated roads, trees, power lines, and most other objects with ice up to 3 inches thick. Travel quickly became difficult to impossible. Many roads including Interstate Highways 90 and 29 were closed for extended periods of time. Most schools and businesses were forced to close. Electric power was lost over widespread areas when many miles of power lines and thousands of poles were knocked down, with more damaged. Strong winds which accompanied the ice storm and the immediately following blizzard combined with the weight of the ice to bring down many of the power lines and poles. Tens of thousands of households and businesses lost power, with the time power was…

5. Apr 10, 2005Thunderstorm Wind$150,000
   National Weather Service narrative

   Thunderstorm winds blew over and heavily damaged a concession stand at a ball park, damaged front of two businesses on Main Street, blew down several trees, damaged several small buildings at nearby farms, and injured several calves.

6. Jun 24, 2003Thunderstorm Wind$100,000
   National Weather Service narrative

   Thunderstorm winds caused tree damage, including numerous trees and large limbs down. Several houses and vehicles were damaged by falling trees or tree debris.

7. Jun 24, 2003Thunderstorm Wind$100,000
   National Weather Service narrative

   Thunderstorm winds caused tree damage, including several trees and large limbs blown down. A few houses sustained roof and siding damage.

8. Jul 27, 1997Thunderstorm Wind$100,000
   National Weather Service narrative

   Thunderstorm winds caused tree and power line damage, and blew out a large window. Minor damage occurred to homes, mainly from wind blown tree debris.

9. May 5, 2007Tornado$100,000
   National Weather Service narrative

   A tornado damaged two farms, including a house shifted off its foundation, and several outbuildings destroyed. The tornado also caused widespread tree damage, including some trees debarked and uprooted. The tornado also blew off the tops of grain bins and blew down power lines.

10. Aug 8, 2009Hail$100,000
    National Weather Service narrative

    Large hail smashed windows on vehicles and buildings, dented vehicles, damaged roofs, and damaged crops. The amount of crop damage was not known.

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

115°FJul 17, 1936

All-time low

−41°FFeb 2, 1905

Warmest night

86°FJul 12, 1901

Coldest day

−22°FFeb 9, 1899

Wettest day

6.10 inMay 21, 1903

Snowiest day

19.0 inJan 19, 1988

Hottest year

2012mean 53.3°F

Coldest year

1951mean 44.5°F

Wettest year

194438.27 in

Driest year

197412.62 in

Snowiest season

73.8 in1959-60

Station Tyndall (USC00398472), 1,420 ft elevation, 1.8 miles from the population centre. Daily records from 1893 to October 23, 2026; 99.6% 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 USC00398472.
• 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.