Hamlin County, South Dakota
County storm and disaster record · FIPS 46057 · population 6,164 · 507 sq mi
NOAA's Storm Events Database holds 634 records for Hamlin County, South Dakota from 1950 through June 30, 2026, on 445 days; the most frequent are hail reports (194 records). The deadliest single record is the January 18, 2010 dense fog, filed for the forecast zone Hamlin, which covers the county: 3 deaths and 2 injuries. FEMA has issued 22 declarations naming the county since 1969, 20 of them for natural hazards; the latest for a natural hazard was “Severe Winter Storms and Snowstorm” on February 27, 2023.
The record, 1950 to 2026
Storm records filed for the county each year (2026 to June 30, 2026). Before 1996 NOAA recorded only tornadoes (from 1950), thunderstorm wind and hail (from 1955).
- recorded, no damage figure
- under $100,000
- $100,000 or more
- $1 million or more
- $10 million or more, or a death
- $100 million or more, or 10 deaths
- a year's colour: its recorded damage or deaths
- a year with a death
- 1955: wind and hail recorded from 1955
- 1996: all 48 event types from 1996
- Storm records
- 634on 445 days, 1950 to June 30, 2026
- Deaths recorded
- 724 injuries
- Damage, 2025 dollars
- $21Mas filed (scale steps before 1993)
- Tornadoes
- 23strongest EF2
- FEMA declarations
- 22latest 2023
Source: NOAA NCEI Storm Events Database, records through June 30, 2026 (file revision 20260918); damage converted to 2025 dollars with the BLS CPI-U. Search the record at NCEI. BLS consumer price index.
What hazards hit Hamlin County most?
The most frequent records are hail reports: 194 since 1964. 55% of its hail reports since 1964 fell in June and July. The rank column places the county among South Dakota's counties by days with a record per 1,000 square miles of land over each hazard's complete period.
| Hazard | Records | Days | First, last | Killed | Injured | Damage | Rank in state |
|---|---|---|---|---|---|---|---|
| Hail | 194 | 103 | 1964-2026 | 0 | 2 | $5.9M | 10 of 66 |
| Winter storms | 132 | 131 | 1996-2026 | 3 | 5 | $48K | 17 of 66 |
| Severe thunderstorm wind | 100 | 63 | 1970-2026 | 1 | 2 | $276K | 20 of 66 |
| Floods | 77 | 65 | 1997-2025 | 0 | 0 | $14M | 8 of 66 |
| Extreme cold | 40 | 40 | 1996-2026 | 0 | 0 | – | 1 of 66 |
| High wind and dust storms | 30 | 30 | 1996-2026 | 0 | 0 | $9K | 42 of 66 |
| Tornadoes | 23 | 17 | 1964-2025 | 0 | 13 | $995K | 15 of 66 |
| Drought | 22 | 22 | 2002-2025 | 0 | 0 | – | 27 of 66 |
| Heat | 10 | 10 | 2006-2025 | 0 | 0 | – | 25 of 66 |
| Fog, smoke and funnel clouds | 6 | 5 | 1999-2025 | 3 | 2 | – | 3 of 66 |
Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.
How many tornadoes has Hamlin County had?
NOAA records 23 tornadoes in Hamlin County from 1964 to 2025, the strongest rated EF2, with 0 deaths and 13 injuries recorded in the county. That is 15th of 66 South Dakota counties by days with tornadoes per 1,000 square miles since 1950. A tornado that crossed a county line is counted in each county it touched, with the length of its path inside the county.
Counted as whole tornadoes rather than county records, the Storm Prediction Center's database holds 24 tornadoes whose track touched Hamlin County since 1950 (NOAA's county records number 23: they file a crossing tornado once per county segment, and the two databases differ on some tracks); along their whole tracks they killed 0 people.
Map of the strongest tornado tracks in South Dakota.
Every tornado record filed for Hamlin County (23)
| Date | Place | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2025-08-16 | Hazel, Hamlin County | EF0 2.46 mi x 75 yd | 0 | 0 | – |
| 2022-05-30 | Dempster, Hamlin County | EF0 0.65 mi x 10 yd | 0 | 0 | – |
| 2022-05-12 | Hazel, Hamlin County | EF1 0.52 mi x 20 yd | 0 | 1 | – |
| 2022-05-12 | Castlewood, Hamlin County | EF2 1.96 mi x 80 yd | 0 | 1 | – |
| 2019-09-09 | Thomas, Hamlin County | EF0 3.2 mi x 40 yd | 0 | 0 | – |
| 2013-06-21 | Lake Norden, Hamlin County | EF0 0.37 mi x 50 yd | 0 | 0 | – |
| 2003-06-24 | Bryant, Hamlin County | F0 0.1 mi x 25 yd | 0 | 0 | – |
| 2001-06-13 | Hazel, Hamlin County | F0 0.1 mi x 25 yd | 0 | 0 | – |
| 1997-06-22 | Lake Norden, Hamlin County | F1 0.5 mi x 25 yd | 0 | 0 | – |
| 1997-06-22 | Hayti, Hamlin County | F0 0.2 mi x 10 yd | 0 | 0 | – |
| 1997-06-22 | Bryant, Hamlin County | F1 0.8 mi x 25 yd | 0 | 0 | – |
| 1996-10-26 | Castlewood, Hamlin County | F1 1 mi x 25 yd | 0 | 0 | $94K |
| 1996-05-18 | Hazel, Hamlin County | F0 0.3 mi x 10 yd | 0 | 0 | – |
| 1986-07-18 | Hamlin County | F2 14 mi x 100 yd | 0 | 0 | $25K step |
| 1984-05-18 | Hamlin County | F0 | 0 | 0 | – |
| 1981-07-22 | Hamlin County | F0 | 0 | 0 | – |
| 1981-07-22 | Hamlin County | F2 | 0 | 0 | $250K step |
| 1980-06-18 | Hamlin County | F0 | 0 | 0 | – |
| 1980-06-18 | Hamlin County | F0 | 0 | 0 | – |
| 1971-06-19 | Hamlin County | F2 36.8 mi x 33 yd | 0 | 0 | – |
| 1967-04-16 | Hamlin County | F1 0.1 mi x 20 yd | 0 | 11 | $3K step |
| 1964-07-10 | Hamlin County | F0 | 0 | 0 | – |
| 1964-07-10 | Hamlin County | 0 | 0 | – |
A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.
Source: NOAA NCEI Storm Events Database, tornado records by county (path length in the county, maximum width); ratings as published: F scale before February 1, 2007, EF scale after. Whole-track figures: NOAA Storm Prediction Center tornado database (1950-2025). SPC severe weather database.
When was the last damaging storm in Hamlin County?
The most recent record with damage, injuries or deaths is the March 12, 2023 winter weather (1 injury).
A rollover accident occurred due to icy roads around 12:40 pm on March 12th, 6 miles northeast of Castlewood near County Road 465 and 183rd Street. The driver was taken to a hospital for injuries from the crash.
National Weather Service event narrative, NOAA Storm Events Database (search the full record, event 1090678)
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2026-06-09 | Thunderstorm WindCastlewood, Hamlin County | 61 kt wind | 0 | 0 | – |
| 2026-06-09 | Thunderstorm WindDempster, Hamlin County | 61 kt wind | 0 | 0 | – |
| 2026-06-09 | Thunderstorm WindDempster, Hamlin County | 61 kt wind | 0 | 0 | – |
| 2026-06-09 | Thunderstorm WindCastlewood, Hamlin County | 61 kt wind | 0 | 0 | – |
| 2026-06-09 | Thunderstorm WindDempster, Hamlin County | 61 kt wind | 0 | 0 | – |
| 2026-06-09 | Thunderstorm WindStone Bridge, Hamlin County | 50 kt wind | 0 | 0 | – |
| 2026-06-09 | Thunderstorm WindStone Bridge, Hamlin County | 61 kt wind | 0 | 0 | – |
| 2026-06-03 | HailCastlewood, Hamlin County | 1.00 in hail | 0 | 0 | – |
| 2026-06-03 | HailThomas, Hamlin County | 1.00 in hail | 0 | 0 | – |
| 2026-03-12 | High WindHamlin County · forecast zone Hamlin | 56 kt wind | 0 | 0 | – |
| 2026-02-28 | Heavy SnowHamlin County · forecast zone Hamlin | 0 | 0 | – | |
| 2026-02-18 | High WindHamlin County · forecast zone Hamlin | 54 kt wind | 0 | 0 | – |
Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.
The deadliest and costliest records
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2010-01-18 | Dense FogHamlin County · forecast zone Hamlin Dense freezing fog created very low visibilities to 1/16 of a mile along with icy roads which contributed to a multi-vehicle wreck 11 miles south of Watertown. The accident killed three people and injured two others. Five vehicles, including a grain truck, were involved in the wreck about 930 am near the intersection ... | 3 | 2 | – | |
| 2011-04-15 | Winter WeatherHamlin County · forecast zone Hamlin One male and one female in their late twenties were killed around 830 am CDT on the 15th on a slushy U.S. Highway 81. The third person in the car was injured-non life threatening. The car they were driving was hit by a large truck. | 2 | 1 | – | |
| 2013-06-21 | Thunderstorm WindStone Bridge, Hamlin County 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. | 78 kt wind | 1 | 2 | $272K |
| 2021-03-10 | Heavy SnowHamlin County · forecast zone Hamlin An area of low pressure tracked through the Central Plains, and brought heavy snow across portions of central and northeastern South Dakota from the morning of the 10th through the early morning of the 11th. Snowfall amounts of 3 to 8 inches accumulated. Some of the highest amounts included 7 inches at Milbank and in ... | 1 | 1 | – | |
| 1967-04-16 | TornadoHamlin County | F1 0.1 mi x 20 yd | 0 | 11 | $3K step |
| 2017-06-22 | HailCastlewood, Hamlin County An early morning storm system impacted parts of central and northeast South Dakota. While large hail fell in the Pierre area, parts of Hamlin and Deuel counties were the hardest hit experiencing winds over 80 mph along with large hail. Northwest of Castlewood, multiple power poles were downed blocking the intersection ... | 1.00 in hail | 0 | 2 | – |
| 1998-03-31 | BlizzardHamlin County · forecast zone Hamlin Heavy snow of 6 to 15 inches combined with 30 to 50 mph winds to generate blizzard conditions across most of northeast South Dakota from noon through the late evening of the 31st. Many roads became snowpacked and impossible to travel on which left many people stranded, especially along Interstate-29 and Highway 12. ... | 0 | 2 | – | |
| 2023-03-12 | Winter WeatherHamlin County · forecast zone Hamlin A rollover accident occurred due to icy roads around 12:40 pm on March 12th, 6 miles northeast of Castlewood near County Road 465 and 183rd Street. The driver was taken to a hospital for injuries from the crash. | 0 | 1 | – |
A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2019-06-01 | FloodHazel, Hamlin County | 0 | 0 | $13M | |
| 1995-09-02 | HailBryant, Hamlin County | 0.75 in hail | 0 | 0 | $5.9M |
| 2011-04-01 | FloodHazel, Hamlin County | 0 | 0 | $1.0M | |
| 2001-04-07 | FloodHamlin County · forecast zone Hamlin | 0 | 0 | $318K | |
| 2013-06-21 | Thunderstorm WindStone Bridge, Hamlin County | 78 kt wind | 1 | 2 | $272K |
| 1996-10-26 | TornadoCastlewood, Hamlin County | F1 1 mi x 25 yd | 0 | 0 | $94K |
Before 1993 NOAA filed damage by category, not amount, so the list above starts in 1993. The highest category filed here before then (entered as $250K, in the dollars of the day) holds: July 22, 1981 (tornado, Hamlin County).
Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.
Is it getting more frequent?
Records per decade for Hamlin County's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).
| Hazard | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020-26 |
|---|---|---|---|---|---|---|---|---|
| Hail | 0 | 2 | 1 | 14 | 25 | 63 | 68 | 21 |
| Winter storms | – | – | – | – | 17 | 33 | 57 | 25 |
| Severe thunderstorm wind | 0 | 0 | 4 | 16 | 12 | 16 | 18 | 34 |
| Floods | – | – | – | – | 6 | 8 | 44 | 19 |
| Extreme cold | – | – | – | – | 1 | 7 | 20 | 12 |
| High wind and dust storms | – | – | – | – | 6 | 7 | 6 | 11 |
Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).
What time of year?
55% of its hail reports since 1964 fell in June and July. The two busiest months are in violet.
The values, month by month
Jan 48 · Feb 35 · Mar 52 · Apr 44 · May 63 · Jun 119 · Jul 95 · Aug 70 · Sep 23 · Oct 14 · Nov 23 · Dec 48 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began.
Federal disaster declarations for Hamlin County
FEMA's register lists 22 declarations that include Hamlin County: 19 major disasters, 3 emergencies and 0 fire management assistance declarations. Most were for flood (9) and severe storm (7).
| Declared | Number | Type | Title |
|---|---|---|---|
| 2023-02-27 | DR-4689 | Winter Storm | Severe Winter Storms and Snowstorm |
| 2022-06-29 | DR-4656 | Severe Storm | Severe Storm, Straight-Line Winds, Tornadoes, and Flooding |
| 2020-04-05 | DR-4527 | Biological | Covid-19 Pandemic |
| 2020-03-13 | EM-3475 | Biological | Covid-19 |
| 2019-09-23 | DR-4463 | Flood | Severe Storms and Flooding |
| 2019-06-07 | DR-4440 | Flood | Severe Winter Storm, Snowstorm, and Flooding |
| 2017-02-01 | DR-4298 | Severe Storm | Severe Winter Storm |
| 2013-08-02 | DR-4137 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| 2011-05-13 | DR-1984 | Flood | Flooding |
| 2010-05-13 | DR-1915 | Flood | Flooding |
| 2005-12-20 | DR-1620 | Severe Storm | Severe Winter Storm |
| 2005-09-10 | EM-3234 | Coastal Storm | Hurricane Katrina Evacuation |
| 2001-05-17 | DR-1375 | Flood | Severe Winter Storms, Flooding, and Ice Jams |
| 1997-04-07 | DR-1173 | Flood | Severe Flooding, Sever Winter Storms,Heavy Rains High Winds |
| 1997-01-10 | DR-1156 | Severe Storm | Severe Winter Storms and Blizzard Conditions |
| 1996-01-05 | DR-1075 | Snowstorm | Severe Winter Storm |
| 1995-05-26 | DR-1052 | Flood | Flooding |
| 1993-07-19 | DR-999 | Severe Storm | Severe Storms, Tornadoes & Flooding |
| 1992-07-02 | DR-948 | Severe Storm | Severe Storms, Tornadoes & Flooding |
| 1986-05-03 | DR-764 | Flood | Severe Storms & Flooding |
| 1976-06-17 | EM-3015 | Drought | Drought |
| 1969-04-18 | DR-257 | Flood | Flooding |
Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.
How many floods has Hamlin County had?
NOAA's Storm Events Database holds 77 flood or flash flood records for Hamlin County from 1997 to 2025, on 65 days, with 0 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Hamlin County ranks 672nd of 2,942 U.S. counties.
The National Flood Insurance Program has paid $4.5 million on 347 claims filed in Hamlin County; the most in one year was 107 in 2011. Claims count insured losses only: uninsured flood damage is not in this file.
The values, year by year
1978: 1 · 1986: 16 · 1992: 1 · 1993: 2 · 1994: 3 · 1997: 60 · 1998: 1 · 2001: 11 · 2009: 1 · 2010: 73 · 2011: 107 · 2012: 1 · 2014: 1 · 2019: 68 · 2020: 1; the other years: 0.
Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.
FEMA's modeled risk for Hamlin County
FEMA's National Risk Index rates Hamlin County Very Low overall, with an expected annual loss of $7.0 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.
| Hazard | Risk rating | Expected annual loss | Modeled frequency |
|---|---|---|---|
| Ice Storm | Relatively Moderate | $203K | once in about 2 years (modeled) |
| Hail | Relatively Low | $489K | 4.3 a year (modeled) |
| Cold Wave | Relatively Low | $1.4M | 13 a year (modeled) |
| Winter Weather | Relatively Low | $90K | 22 a year (modeled) |
| Strong Wind | Relatively Low | $683K | 3.1 a year (modeled) |
| Drought | Relatively Low | $99K | 4.4 modeled event-days a year |
| Tornado | Relatively Low | $980K | once in about 3 years (modeled) |
| Wildfire | Very Low | $60K | once in about 1,924 years (modeled) |
Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.
Counties that share a border with Hamlin County
Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.
Next
- Tornadoes in South DakotaEvery South Dakota tornado since 1950 and the counties with the most per square mile
- Hail in South DakotaThe state's hail reports, by county, year and month
- The South Dakota recordEvery hazard in the state, its deadliest events and its federal declarations
- FEMA's risk rating for each hazard in Hamlin CountyThe hazard risk calculator: 18 hazards beside the county's record
- Download Hamlin County's FEMA declarations (CSV)22 rows: every declaration that named the county, for your own analysis