Sweet Grass County, Montana
County storm and disaster record · FIPS 30097 · population 3,674 · 1,856 sq mi
NOAA's Storm Events Database holds 1,045 records for Sweet Grass County, Montana from 1950 through June 30, 2026, on 640 days; the most frequent are winter storm records (492 records). 853 of them are forecast-zone records, which the National Weather Service files once per zone: a county covered by several zones receives each one, so a single storm can add several records on the same day. The deadliest single record is the December 27, 2021 avalanche, filed for the forecast zone Absaroka / Beartooth Mountains, which covers the county: 1 death and 2 injuries. FEMA has issued 10 declarations naming the county since 1997, 8 of them for natural hazards; the latest for a natural hazard was “Severe Winter Storm and Straight-Line Winds” on April 7, 2026.
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
- 1,045on 640 days, 1950 to June 30, 2026
- Deaths recorded
- 113 injuries
- Damage, 2025 dollars
- $7.8Mas filed (scale steps before 1993)
- Tornadoes
- 2strongest F1
- FEMA declarations
- 10latest 2026
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 Sweet Grass County most?
The most frequent records are winter storm records: 492 since 2002. The rank column places the county among Montana'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 |
|---|---|---|---|---|---|---|---|
| Winter storms | 492 | 285 | 2002-2026 | 1 | 0 | – | 11 of 56 |
| High wind and dust storms | 332 | 247 | 2005-2026 | 0 | 0 | – | 7 of 56 |
| Hail | 130 | 62 | 1955-2025 | 0 | 0 | – | 26 of 56 |
| Severe thunderstorm wind | 41 | 31 | 1988-2026 | 0 | 0 | $995K | 41 of 56 |
| Wildfires | 13 | 11 | 1998-2021 | 0 | 0 | $1.6M | 7 of 56 |
| Floods | 12 | 11 | 1997-2023 | 0 | 0 | $5.2M | 35 of 56 |
| Landslides and avalanches | 11 | 11 | 2010-2025 | 10 | 3 | – | 2 of 56 |
| Drought | 5 | 1 | 2021-2021 | 0 | 0 | – | 18 of 56 |
| Heavy rain | 5 | 3 | 1998-2005 | 0 | 0 | – | 36 of 56 |
| Fog, smoke and funnel clouds | 2 | 2 | 2011-2013 | 0 | 0 | – | 37 of 56 |
| Tornadoes | 2 | 2 | 1965-1973 | 0 | 0 | $199 | 41 of 56 |
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 Sweet Grass County had?
NOAA records 2 tornadoes in Sweet Grass County from 1965 to 1973, the strongest rated F1, 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 2 tornadoes whose track touched Sweet Grass County since 1950 (NOAA's county records number 2, the same count); along their whole tracks they killed 0 people.
Map of the strongest tornado tracks in Montana.
Every tornado record filed for Sweet Grass County (2)
| Date | Place | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 1973-05-20 | Sweet Grass County | F0 0.1 mi x 17 yd | 0 | 0 | $30 step |
| 1965-08-22 | Sweet Grass County | F1 1.5 mi x 33 yd | 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 Sweet Grass County?
The most recent record with damage, injuries or deaths is the December 31, 2022 avalanche (1 death).
Please see Episode write-up.
National Weather Service event narrative, NOAA Storm Events Database (search the full record, event 1062787)
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2026-05-20 | Winter StormCarbon County and 3 more · forecast zone Absaroka / Beartooth Mountains | 0 | 0 | – | |
| 2026-05-14 | High WindSweet Grass County and Wheatland County · forecast zone Melville Foothills | 63 kt wind | 0 | 0 | – |
| 2026-05-13 | High WindSweet Grass County · forecast zone Northern Sweet Grass | 62 kt wind | 0 | 0 | – |
| 2026-05-13 | Thunderstorm WindBig Timber Airport, Sweet Grass County | 60 kt wind | 0 | 0 | – |
| 2026-05-13 | Thunderstorm WindMc Leod, Sweet Grass County | 50 kt wind | 0 | 0 | – |
| 2026-05-13 | Thunderstorm WindMelville, Sweet Grass County | 54 kt wind | 0 | 0 | – |
| 2026-05-13 | Thunderstorm WindBig Timber Airport, Sweet Grass County | 58 kt wind | 0 | 0 | – |
| 2026-04-22 | Winter StormCarbon County and 3 more · forecast zone Absaroka / Beartooth Mountains | 0 | 0 | – | |
| 2026-04-22 | Winter StormPark County and 2 more · forecast zone Crazy Mountains | 0 | 0 | – | |
| 2026-04-15 | Winter StormCarbon County and 3 more · forecast zone Absaroka / Beartooth Mountains | 0 | 0 | – | |
| 2026-04-15 | Winter StormPark County and 2 more · forecast zone Crazy Mountains | 0 | 0 | – | |
| 2026-04-07 | High WindSweet Grass County · forecast zone Northern Sweet Grass | 52 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 |
|---|---|---|---|---|---|
| 2021-12-27 | AvalancheCarbon County and 3 more · forecast zone Absaroka / Beartooth Mountains Please see episode narrative. | 1 | 2 | – | |
| 2022-02-19 | AvalancheCarbon County and 3 more · forecast zone Absaroka / Beartooth Mountains Please see Episode Narrative. | 1 | 1 | – | |
| 2022-12-31 | AvalancheCarbon County and 3 more · forecast zone Absaroka / Beartooth Mountains Please see Episode write-up. | 1 | 0 | – | |
| 2019-11-05 | Winter WeatherSweet Grass County · forecast zone Northern Sweet Grass Freezing drizzle and black ice were reported across the area. A fatal car crash occurred in Sweet Grass County at about 10:01 am on I-90 west of Big Timber near mile marker 364. The rollover crash occurred after the driver lost control on the icy roadway and entered the center median, rolling once. The driver, a ... | 1 | 0 | – | |
| 2016-12-11 | AvalancheCarbon County and 3 more · forecast zone Absarokee / Beartooth Mountains A skier was killed by an avalanche on Henderson Mountain outside Cooke City on December 11th. The skier was in a party of 5 and his descent was the 7th track on the slope when it avalanched. He was carried into trees and buried under 5' of snow. Another person was buried to his waist, uninjured, as he stood in the ... | 1 | 0 | – | |
| 2015-12-19 | AvalancheCarbon County and 3 more · forecast zone Absarokee / Beartooth Mountains A snowmobiler died in an avalanche on Saturday, December 19th outside Cooke City. The avalanche occurred on the southeast face of Sheep Mountain between Lulu Pass and Round Lake. The slide was triggered from low on the slope by the victim who was subsequently buried six fee deep. The victim had an airbag but was ... | 1 | 0 | – | |
| 2014-11-26 | AvalancheCarbon County and 3 more · forecast zone Absarokee / Beartooth Mountains A group of seven snowmobilers was riding north of Cooke City when an 18 year old from Minnesota was caught in an avalanche on a steep, northwest facing slope on Crown Butte outside Cooke City. The victim was stopped on the slope while two others were riding on it when the avalanche was triggered. The others rode off, ... | 1 | 0 | – | |
| 2014-03-11 | AvalancheCarbon County and 3 more · forecast zone Absarokee / Beartooth Mountains A group of seven snowmobilers was riding north of Cooke City when an 18 year old from Minnesota was caught in an avalanche on a steep, northwest facing slope on Crown Butte outside Cooke City. The victim was stopped on the slope while two others were riding on it when the avalanche was triggered. The others rode off, ... | 1 | 0 | – |
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2011-05-20 | FloodMelville, Sweet Grass County | 0 | 0 | $5.2M | |
| 2003-08-06 | WildfireSweet Grass County · forecast zone Sweet Grass | 0 | 0 | $1.6M |
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 $30, in the dollars of the day) holds: May 20, 1973 (tornado, Sweet Grass 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 Sweet Grass 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 |
|---|---|---|---|---|---|---|---|---|
| Winter storms | – | – | – | – | 0 | 126 | 200 | 166 |
| High wind and dust storms | – | – | – | – | 0 | 53 | 99 | 180 |
| Hail | 2 | 0 | 0 | 3 | 14 | 37 | 69 | 5 |
| Severe thunderstorm wind | 0 | 0 | 0 | 1 | 3 | 5 | 15 | 17 |
| Wildfires | – | – | – | – | 2 | 6 | 3 | 2 |
| Floods | – | – | – | – | 2 | 3 | 4 | 3 |
Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).
What time of year?
Records by month in Sweet Grass County. The two busiest months are in violet.
The values, month by month
Jan 124 · Feb 145 · Mar 109 · Apr 87 · May 67 · Jun 85 · Jul 54 · Aug 40 · Sep 18 · Oct 84 · Nov 101 · Dec 131 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began.
Federal disaster declarations for Sweet Grass County
FEMA's register lists 10 declarations that include Sweet Grass County: 6 major disasters, 2 emergencies and 2 fire management assistance declarations. Most were for fire (3) and biological (2).
| Declared | Number | Type | Title |
|---|---|---|---|
| 2026-04-07 | DR-4902 | Straight-Line Winds | Severe Winter Storm and Straight-Line Winds |
| 2022-06-16 | DR-4655 | Flood | Severe Storm and Flooding |
| 2020-03-31 | DR-4508 | Biological | Covid-19 Pandemic |
| 2020-03-13 | EM-3476 | Biological | Covid-19 |
| 2011-06-17 | DR-1996 | Severe Storm | Severe Storms and Flooding |
| 2006-08-30 | FM-2671 | Fire | Derby Fire |
| 2005-09-13 | EM-3253 | Hurricane | Hurricane Katrina Evacuation |
| 2003-08-11 | FM-2488 | Fire | Mt-Hobble Fire-08/07/2003 |
| 2000-08-30 | DR-1340 | Fire | Wildfires |
| 1997-07-25 | DR-1183 | Severe Storm | Severe Storms,Ice Jams, Snow Melt, 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 Sweet Grass County had?
NOAA's Storm Events Database holds 12 flood or flash flood records for Sweet Grass County from 1997 to 2023, on 11 days, with 0 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Sweet Grass County ranks 2358th of 2,942 U.S. counties.
The National Flood Insurance Program has paid $419,000 on 10 claims filed in Sweet Grass County; the most in one year was 7 in 1997. Claims count insured losses only: uninsured flood damage is not in this file.
The values, year by year
1997: 7 · 2011: 1 · 2018: 1 · 2022: 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 Sweet Grass County
FEMA's National Risk Index rates Sweet Grass County Very Low overall, with an expected annual loss of $5.9 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 | $1.5M | once in about 807 years (modeled) |
| Winter Weather | Relatively Low | $46K | 23 a year (modeled) |
| Cold Wave | Relatively Low | $578K | 2.4 a year (modeled) |
| Avalanche | Very Low | $2K | once in about 8 years (modeled) |
| Landslide | Very Low | $3K | 2.3 a year (modeled) |
| Earthquake | Very Low | $157K | once in about 203 years (modeled) |
| Hail | Very Low | $109K | 1.3 a year (modeled) |
| Riverine Flooding | Very Low | $3.4M | once in about 3 years (modeled) |
Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.
Counties that share a border with Sweet Grass 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 MontanaEvery Montana tornado since 1950 and the counties with the most per square mile
- Winter storms in MontanaThe state's winter storm records, by county, year and month
- The Montana recordEvery hazard in the state, its deadliest events and its federal declarations
- FEMA's risk rating for each hazard in Sweet Grass CountyThe hazard risk calculator: 18 hazards beside the county's record
- Download Sweet Grass County's FEMA declarations (CSV)10 rows: every declaration that named the county, for your own analysis