Mellette County, South Dakota
County storm and disaster record · FIPS 46095 · population 1,879 · 1,307 sq mi
NOAA's Storm Events Database holds 488 records for Mellette County, South Dakota from 1950 through June 30, 2026, on 366 days; the most frequent are hail reports (164 records). The deadliest single record is the December 12, 2022 blizzard, filed for the forecast zone Mellette, which covers the county: 1 death. FEMA has issued 14 declarations naming the county since 1976, 12 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
- 488on 366 days, 1950 to June 30, 2026
- Deaths recorded
- 11 injuries
- Damage, 2025 dollars
- $3.5Mas filed (scale steps before 1993)
- Tornadoes
- 12strongest F2
- FEMA declarations
- 14latest 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 Mellette County most?
The most frequent records are hail reports: 164 since 1971. 55% of its hail reports since 1971 fell in July and August. 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 | 164 | 107 | 1971-2026 | 0 | 0 | $350K | 58 of 66 |
| Severe thunderstorm wind | 116 | 85 | 1966-2026 | 0 | 1 | $564K | 63 of 66 |
| Winter storms | 109 | 108 | 1996-2025 | 1 | 0 | $722K | 48 of 66 |
| High wind and dust storms | 57 | 56 | 1996-2026 | 0 | 0 | – | 59 of 66 |
| Floods | 16 | 16 | 1996-2024 | 0 | 0 | $146K | 58 of 66 |
| Tornadoes | 12 | 11 | 1969-2000 | 0 | 0 | $1.7M | 57 of 66 |
| Extreme cold | 11 | 11 | 1996-2025 | 0 | 0 | – | 53 of 66 |
| Heat | 1 | 1 | 2006-2006 | 0 | 0 | – | 53 of 66 |
| Heavy rain | 1 | 1 | 1998-1998 | 0 | 0 | – | 26 of 66 |
| Fog, smoke and funnel clouds | 1 | 1 | 1998-1998 | 0 | 0 | – | 52 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 Mellette County had?
NOAA records 12 tornadoes in Mellette County from 1969 to 2000, the strongest rated F2, with 0 deaths and 0 injuries recorded in the county. 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 11 tornadoes whose track touched Mellette County since 1950 (NOAA's county records number 12: 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 Mellette County (12)
| Date | Place | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2000-07-24 | Mosher, Mellette County | F0 1 mi x 100 yd | 0 | 0 | – |
| 2000-07-15 | Norris, Mellette County | F0 0.5 mi x 10 yd | 0 | 0 | – |
| 1999-05-09 | White River, Mellette County | F0 0.1 mi x 1 yd | 0 | 0 | – |
| 1999-05-09 | White River, Mellette County | F0 0.1 mi x 1 yd | 0 | 0 | – |
| 1998-07-01 | Norris, Mellette County | F0 | 0 | 0 | – |
| 1997-06-11 | White River, Mellette County | F0 0.1 mi x 1 yd | 0 | 0 | – |
| 1987-07-10 | Mellette County | F0 0.1 mi x 20 yd | 0 | 0 | – |
| 1986-09-24 | Mellette County | F0 1.5 mi x 60 yd | 0 | 0 | $25K step |
| 1974-05-19 | Mellette County | F1 | 0 | 0 | $250K step |
| 1973-07-04 | Mellette County | F1 0.5 mi x 83 yd | 0 | 0 | $25K step |
| 1971-06-04 | Mellette County | F2 0.3 mi x 50 yd | 0 | 0 | – |
| 1969-07-10 | Mellette 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 Mellette County?
The most recent record with damage, injuries or deaths is the December 12, 2022 blizzard (1 death).
A powerful winter storm moved slowly across the central and northern Plains to the upper Midwest; bringing heavy snow, some mixed precipitation, strong winds, and periods of blizzard or near blizzard conditions across the plains for a multi-day period. Snowfall was heaviest from northwestern to south central South Dakota and across the northern Black Hills. Precipitation started as a mix in the form of rain, freezing rain, and freezing drizzle across much of the plains, then changed to snow in most areas by the daytime hours on the 13th. Bands of snow were moderate to heavy at times in many areas, with a very prolonged period of upslope enhanced snowfall across the northern Black Hills. Amounts across the area ranged from one foot to over two feet across much of the plains, with the highest amounts generally from Oglala Lakota County into parts of south central South Dakota. …
National Weather Service event narrative, NOAA Storm Events Database (search the full record, event 1062629)
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2026-06-29 | Thunderstorm WindWhite River, Mellette County | 61 kt wind | 0 | 0 | – |
| 2026-06-29 | HailWhite River, Mellette County | 1.00 in hail | 0 | 0 | – |
| 2026-06-09 | Thunderstorm WindWhite River, Mellette County | 52 kt wind | 0 | 0 | – |
| 2026-06-02 | Thunderstorm WindWhite River, Mellette County | 52 kt wind | 0 | 0 | – |
| 2026-06-02 | HailWhite River, Mellette County | 1.50 in hail | 0 | 0 | – |
| 2026-01-21 | High WindMellette County · forecast zone Mellette | 56 kt wind | 0 | 0 | – |
| 2025-12-18 | High WindMellette County · forecast zone Mellette | 67 kt wind | 0 | 0 | – |
| 2025-12-18 | High WindMellette County · forecast zone Mellette | 67 kt wind | 0 | 0 | – |
| 2025-12-17 | High WindMellette County · forecast zone Mellette | 56 kt wind | 0 | 0 | – |
| 2025-08-13 | Thunderstorm WindWhite River, Mellette County | 55 kt wind | 0 | 0 | – |
| 2025-08-13 | Thunderstorm WindWhite River, Mellette County | 51 kt wind | 0 | 0 | – |
| 2025-08-13 | Thunderstorm WindCedar Butte, Mellette County | 55 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 |
|---|---|---|---|---|---|
| 2022-12-12 | BlizzardMellette County · forecast zone Mellette A powerful winter storm moved slowly across the central and northern Plains to the upper Midwest; bringing heavy snow, some mixed precipitation, strong winds, and periods of blizzard or near blizzard conditions across the plains for a multi-day period. Snowfall was heaviest from northwestern to south central South ... | 1 | 0 | – | |
| 2012-07-22 | Thunderstorm WindWood, Mellette County Strong winds destroyed two trailer houses, damaged the school roof, and knocked down several power poles. A woman in one of the mobile homes was severely injured. | 70 kt wind | 0 | 1 | $77K |
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2009-03-30 | BlizzardMellette County · forecast zone Mellette | 0 | 0 | $413K | |
| 2000-08-20 | Thunderstorm WindWhite River, Mellette County | 0 | 0 | $343K | |
| 2007-07-09 | Thunderstorm WindWhite River, Mellette County | 70 kt wind | 0 | 0 | $107K |
| 2012-07-22 | Thunderstorm WindWood, Mellette County | 70 kt wind | 0 | 1 | $77K |
| 2013-07-30 | HailNorris, Mellette County | 2.50 in hail | 0 | 0 | $63K |
| 2009-07-13 | HailCedar Butte, Mellette County | 2.75 in hail | 0 | 0 | $55K |
| 2011-08-17 | HailCedar Butte, Mellette County | 2.75 in hail | 0 | 0 | $52K |
| 1997-06-01 | HailCedar Butte, Mellette County | 3.00 in hail | 0 | 0 | $46K |
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: May 19, 1974 (tornado, Mellette 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 Mellette 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 | 0 | 3 | 5 | 21 | 72 | 33 | 30 |
| Severe thunderstorm wind | 0 | 1 | 1 | 2 | 7 | 31 | 40 | 34 |
| Winter storms | – | – | – | – | 10 | 29 | 41 | 29 |
| High wind and dust storms | – | – | – | – | 7 | 13 | 15 | 22 |
| Floods | – | – | – | – | 3 | 5 | 6 | 2 |
| Tornadoes | 0 | 1 | 3 | 2 | 4 | 2 | 0 | 0 |
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 1971 fell in July and August. The two busiest months are in violet.
The values, month by month
Jan 30 · Feb 28 · Mar 36 · Apr 27 · May 39 · Jun 87 · Jul 83 · Aug 85 · Sep 10 · Oct 14 · Nov 17 · Dec 32 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began.
Federal disaster declarations for Mellette County
FEMA's register lists 14 declarations that include Mellette County: 11 major disasters, 3 emergencies and 0 fire management assistance declarations. Most were for flood (4) and severe storm (4).
| Declared | Number | Type | Title |
|---|---|---|---|
| 2023-02-27 | DR-4689 | Winter Storm | Severe Winter Storms and Snowstorm |
| 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 |
| 2010-03-09 | DR-1886 | Severe Storm | Severe Winter Storm and Snowstorm |
| 2008-12-12 | DR-1811 | Snowstorm | Severe Winter Storm and Record and Near Record Snow |
| 2008-07-09 | DR-1774 | Severe Storm | Severe Storms and Flooding |
| 2005-09-10 | EM-3234 | Coastal Storm | Hurricane Katrina Evacuation |
| 2004-07-20 | DR-1531 | Severe Storm | Severe Storms and Flooding |
| 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 |
| 1976-06-17 | EM-3015 | Drought | Drought |
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.
FEMA's modeled risk for Mellette County
FEMA's National Risk Index rates Mellette County Very Low overall, with an expected annual loss of $1.9 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 |
|---|---|---|---|
| Wildfire | Relatively Low | $348K | once in about 615 years (modeled) |
| Winter Weather | Relatively Low | $54K | 15 a year (modeled) |
| Cold Wave | Relatively Low | $443K | 5.5 a year (modeled) |
| Ice Storm | Relatively Low | $23K | once in about 3 years (modeled) |
| Strong Wind | Relatively Low | $88K | 2.7 a year (modeled) |
| Drought | Very Low | $16K | 43 modeled event-days a year |
| Landslide | Very Low | $97 | once in about 2 years (modeled) |
| Hail | Very Low | $48K | 3.3 a year (modeled) |
Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.
Counties that share a border with Mellette 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 Mellette CountyThe hazard risk calculator: 18 hazards beside the county's record
- Download Mellette County's FEMA declarations (CSV)14 rows: every declaration that named the county, for your own analysis