Hamlin County

Every recorded tornado

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

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. Apr 1, 2011Flood$800,000
   National Weather Service narrative

   Snowmelt flooding damaged many roads and highways, including U.S. Highway 81, throughout Hamlin County. Many roads were closed throughout the county. In the late evening of April 13th on U.S Highway 81, a car with four people inside went through a flooded area at a high rate of speed and ended up in the flooded ditch. They all got out with no injuries.

2. Jun 21, 2013Thunderstorm Wind$215,000
   National Weather Service narrative

   Severe tree and structural damage occurred on Lake Poinsett with ninety mph winds. A woman was killed and her husband was seriously injured when their lake house was destroyed. A man was also hospitalized for electric shock.

3. Apr 1, 2019Flood$202,000
   National Weather Service narrative

   The continuation of snowmelt from a much above normal snowfall winter combined with a historic heavy snow/blizzard in mid-April resulted in widespread flooding across central and northeast South Dakota. Countless roads along with thousands of acres of cropland were flooded throughout April. Impacts include damaged roads, culverts, and bridges, and livestock, homes, and businesses were affected. Delayed planting resulted across all of the region as well. Cattle and calves were stressed by the cold and wet pattern, as the mud and cold caused some sickness with the livestock. Flooded roads made it difficult for many farmers or ranchers to get to their fields or livestock. There was a…

4. Apr 7, 2001Flood, Hamlin$191,000
   National Weather Service narrative

   Heavy rain of 1 to 3 inches combined with snowmelt runoff brought flooding to parts of northeast South Dakota. Many roads across Clark, Grant, Hamlin, Deuel, and Roberts counties were flooded and damaged. Floodwater moving towards the town of Willow Lake overpowered culverts and flooded several homes and several streets. Highway 28 had to be cut through to allow the water to flow away from the town, averting a disaster. Highwater from the creek west of Corona in far Southern Roberts county flowed towards Corona. As a result, 3 1/2 feet of water coursed through town flooding several homes and streets and knocking out the sewer system. Also, 1000 feet of railroad track was damaged…

5. Mar 22, 2009Flash Flood$50,000
   National Weather Service narrative

   Warm frontal thunderstorms produced 1 to 3 inches of heavy rain across Grant, Deuel, Hamlin, and Codington counties. The heavy rain fell on top of an extensive snow cover resulting in flash flooding. Many roads were over topped with several locations washed out, especially in Deuel County.

6. Oct 26, 1996Tornado$50,000
   National Weather Service narrative

   A tornado touched down at a farm east of Castlewood and took most of a 40 by 60 foot cattle shed and deposited in a cornfield across the road to the north. Several doors of buildings were torn off their hinges with one door thrown into some trees. A 2 X 6 was driven into the gravel road. Power lines were also downed leaving the farm without power until late in the day. The tornado proceeded north across Highway 22 where it ripped apart a new calf shed at another farm, tipped an elevator over, and pushed a three stall garage off of it's foundation. Alot of tree damage occurred at both farms. Path length and width were estimated.

7. Jun 26, 2010Flash Flood$50,000
   National Weather Service narrative

   Many township roads were flooded throughout Hamlin county with several of the roads being washed out.

8. Dec 25, 2016Ice Storm, Hamlin$31,000
   National Weather Service narrative

   An intense surface low pressure area moved from northeast Colorado to South Dakota from the 24th through the 26th. This storm was unusually warm for the region for late December and produced record breaking heavy rain along with flooding in some cases. Significant icing occurred across areas at or just below the freezing point, which resulted in widespread tree and power pole and line damage to the area. Some downed branches and trees fell onto homes across the region. This storm also brought high winds along with snow and blizzard conditions to the region. This significant storm resulted in massive power outages, stranded motorists and closed roads. ||Ice accumulations were…

9. Mar 24, 1996Blizzard, Hamlin$5,000
   National Weather Service narrative

   Snow accumulating 3 to 8 inches was accompanied by winds over 50 mph at times, producing widespread whiteout conditions. Numerous vehicles slid into ditches and many people were stranded in vehicles. There were some rollovers and other accidents, including a fatality near Tripp in Hutchinson County. Some power outages occurred due to downed or whipping power lines. Other damage was caused by the strong winds, including the roof blown off of a golf clubhouse at Parker in Turner County. Many roads, including interstate highways, were closed or blocked, and schools and businesses were closed or forced to delay opening on the 25th. Wind chills were as low as 40 below zero.

10. Feb 10, 1996High Wind, Hamlin$5,000
    National Weather Service narrative

    Strong gradient winds with gusts to 67 mph spread across eastern South Dakota on the morning of February 10th and continued into the early evening hours. Small structures were blown over or otherwise damaged, and damage occurred to homes and other large structures; mainly roof damage. A few semis andother high profile vehicles were overturned. A small airplane was overturned at Sioux Falls. Visibility was reduced greatly at times in parts of the area because of blowing snow and blowing dust.

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°FJul 21, 1934

All-time low

−40°FJan 13, 1916

Warmest night

78°F4 times, most recently Jul 16, 2012

Coldest day

−25°FFeb 8, 1899

Wettest day

7.14 inMay 27, 1931

Snowiest day

19.0 inApr 25, 2008

Hottest year

1987mean 48.7°F

Coldest year

1917mean 38.5°F

Wettest year

197740.04 in

Driest year

197610.82 in

Snowiest season

81.7 in2018-19

Station Watertown Regional Airport (USW00014946), 1,741 ft elevation, 17.8 miles from the population centre. Daily records from 1893 to October 26, 2026; 99.8% 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 USW00014946.
• 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.