Sweetwater County, Wyoming
County storm and disaster record · FIPS 56037 · population 42,238 · 10,427 sq mi
NOAA's Storm Events Database holds 864 records for Sweetwater County, Wyoming from 1950 through June 30, 2026, on 592 days; the most frequent are high wind and dust records (382 records). 671 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 June 23, 2018 strong wind, filed for the forecast zone Flaming Gorge, which covers the county: 1 death and 2 injuries. FEMA has issued 4 declarations naming the county since 1977, 2 of them for natural hazards; the latest for a natural hazard was “Severe Storms, Flooding, and Landslides” on July 22, 2011.
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
- 864on 592 days, 1950 to June 30, 2026
- Deaths recorded
- 115 injuries
- Damage, 2025 dollars
- $3.4Mas filed (scale steps before 1993)
- Tornadoes
- 26strongest F1
- FEMA declarations
- 4latest 2020
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 Sweetwater County most?
The most frequent records are high wind and dust records: 382 since 1997. The rank column places the county among Wyoming'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 |
|---|---|---|---|---|---|---|---|
| High wind and dust storms | 382 | 288 | 1997-2026 | 1 | 2 | $171K | 13 of 23 |
| Winter storms | 226 | 132 | 1996-2026 | 0 | 1 | $46K | 23 of 23 |
| Severe thunderstorm wind | 124 | 97 | 1957-2026 | 0 | 11 | $81K | 20 of 23 |
| Extreme cold | 33 | 14 | 1996-2025 | 0 | 0 | – | 21 of 23 |
| Tornadoes | 26 | 23 | 1960-2025 | 0 | 0 | $202K | 17 of 23 |
| Fog, smoke and funnel clouds | 22 | 16 | 1997-2016 | 0 | 0 | – | 16 of 23 |
| Heat | 16 | 8 | 2019-2026 | 0 | 0 | – | 11 of 23 |
| Hail | 13 | 13 | 1980-2023 | 0 | 0 | $963K | 23 of 23 |
| Floods | 12 | 12 | 1998-2024 | 0 | 0 | $1.5M | 21 of 23 |
| Wildfires | 8 | 8 | 2000-2020 | 0 | 0 | $428K | 17 of 23 |
| Landslides and avalanches | 1 | 1 | 2019-2019 | 0 | 0 | – | 15 of 23 |
| Lightning | 1 | 1 | 2014-2014 | 0 | 1 | – | 19 of 23 |
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 Sweetwater County had?
NOAA records 26 tornadoes in Sweetwater County from 1960 to 2025, 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 26 tornadoes whose track touched Sweetwater County since 1950 (NOAA's county records number 26, the same count); along their whole tracks they killed 0 people.
Map of the strongest tornado tracks in Wyoming.
Every tornado record filed for Sweetwater County (26)
| Date | Place | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2025-07-01 | Farson, Sweetwater County | EF0 0.79 mi x 25 yd | 0 | 0 | – |
| 2023-06-23 | Granger, Sweetwater County | EFU 0.09 mi x 30 yd | 0 | 0 | – |
| 2018-05-28 | Granger, Sweetwater County | EF0 3.45 mi x 25 yd | 0 | 0 | – |
| 2017-05-26 | Table Rock, Sweetwater County | EF0 11.36 mi x 30 yd | 0 | 0 | $1K |
| 2015-07-07 | Red Desert, Sweetwater County | EF0 0.05 mi x 10 yd | 0 | 0 | – |
| 2014-05-07 | Eden, Sweetwater County | EF0 0.53 mi x 30 yd | 0 | 0 | – |
| 2013-09-15 | Eden, Sweetwater County | EF0 0.05 mi x 30 yd | 0 | 0 | – |
| 2003-06-24 | Rock Spgs, Sweetwater County | F0 | 0 | 0 | – |
| 2001-04-20 | James Town, Sweetwater County | F1 0.2 mi x 10 yd | 0 | 0 | – |
| 2000-04-14 | James Town, Sweetwater County | F1 0.5 mi x 50 yd | 0 | 0 | $51K |
| 1997-06-10 | Rock Spgs Airport, Sweetwater County | F0 0.1 mi x 30 yd | 0 | 0 | – |
| 1995-05-25 | Sweetwater County | F0 0.5 mi x 50 yd | 0 | 0 | – |
| 1992-05-15 | Sweetwater County | F0 0.1 mi x 10 yd | 0 | 0 | – |
| 1991-09-09 | Sweetwater County | F0 0.4 mi x 40 yd | 0 | 0 | – |
| 1990-08-04 | Sweetwater County | F0 0.1 mi x 10 yd | 0 | 0 | – |
| 1990-07-24 | Sweetwater County | F0 0.1 mi x 10 yd | 0 | 0 | – |
| 1989-05-30 | Sweetwater County | F0 0.5 mi x 100 yd | 0 | 0 | – |
| 1989-05-30 | Sweetwater County | F0 0.5 mi x 50 yd | 0 | 0 | – |
| 1982-06-14 | Sweetwater County | F0 0.1 mi x 3 yd | 0 | 0 | $30 step |
| 1979-08-14 | Sweetwater County | F0 | 0 | 0 | – |
| 1979-08-14 | Sweetwater County | F0 | 0 | 0 | – |
| 1979-08-14 | Sweetwater County | F0 1 mi x 200 yd | 0 | 0 | – |
| 1978-07-31 | Sweetwater County | F1 1 mi x 100 yd | 0 | 0 | – |
| 1974-06-27 | Sweetwater County | F1 0.1 mi x 33 yd | 0 | 0 | $25K step |
| 1973-09-09 | Sweetwater County | F1 | 0 | 0 | – |
| 1960-06-09 | Sweetwater County | F0 0.1 mi x 17 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 Sweetwater County?
The most recent record with damage, injuries or deaths is the December 10, 2025 high wind ($10,000 in damage in 2025 dollars).
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2026-06-29 | High WindFremont County and 2 more · forecast zone Green Mountains & Rattlesnake Range | 53 kt wind | 0 | 0 | – |
| 2026-06-26 | High WindSweetwater County · forecast zone East Sweetwater County | 50 kt wind | 0 | 0 | – |
| 2026-06-20 | Thunderstorm WindEden, Sweetwater County | 64 kt wind | 0 | 0 | – |
| 2026-06-20 | Thunderstorm WindRock Spgs, Sweetwater County | 61 kt wind | 0 | 0 | – |
| 2026-06-20 | Thunderstorm WindRock Spgs Airport, Sweetwater County | 52 kt wind | 0 | 0 | – |
| 2026-06-10 | High WindFremont County and 3 more · forecast zone Upper Green River Basin | 58 kt wind | 0 | 0 | – |
| 2026-06-10 | High WindFremont County and 2 more · forecast zone Green Mountains & Rattlesnake Range | 55 kt wind | 0 | 0 | – |
| 2026-06-07 | Thunderstorm WindBitter Creek, Sweetwater County | 55 kt wind | 0 | 0 | – |
| 2026-06-07 | Thunderstorm WindRock Spgs Airport, Sweetwater County | 58 kt wind | 0 | 0 | – |
| 2026-06-02 | Thunderstorm WindGreen River, Sweetwater County | 50 kt wind | 0 | 0 | – |
| 2026-05-24 | Thunderstorm WindRock Spgs Airport, Sweetwater County | 51 kt wind | 0 | 0 | – |
| 2026-05-17 | Winter StormSweetwater County · forecast zone East Sweetwater County | 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 |
|---|---|---|---|---|---|
| 2018-06-23 | Strong WindSweetwater County · forecast zone Flaming Gorge A boat capsized around 3.5 miles southeast of the Buckboard Marina on Flaming Gorge reservoir around 1 pm after gusty winds developed and the water became choppy. The boat was swamped and eventually capsized. A 48 year old man drowned as a result. He was the only one not wearing a life vest. Two other men suffered ... | 35 kt wind | 1 | 2 | – |
| 2000-08-01 | Thunderstorm WindRock Spgs, Sweetwater County Large tent at county fairgrounds was blown over. No serious injuries reported. The injured were treated and released from the hospital. | 0 | 10 | – | |
| 2014-05-24 | LightningReliance, Sweetwater County A 31-year-old man was injured when lightning struck him on the practice putting green at White Mountain Golf Course on the north side of Rock Springs. A witness to the incident was able to revive the man with CPR and a defibrillator. | 0 | 1 | – | |
| 2000-06-05 | Thunderstorm WindRock Spgs, Sweetwater County A dry microburst occured in the Rock Springs area. The storm ripped off two roofs and downed power lines and trees. A woman was injured by the storm. Also, an unoffical wind gust of 68 mph was reported at a radio station 2 miles north of Rock Springs. | 0 | 1 | – | |
| 1998-04-14 | Heavy SnowSweetwater County · forecast zone East Johnson Two-day storm dumped up to 3 feet of snow on parts of Johnson County, with the heaviest amounts near the town of Buffalo. Roads (including I-25 and I-90) and schools were closed, and tree limbs and power lines were down in Buffalo. Lesser amounts fell over northwest Wyoming, with 7 to 12 inches reported from central ... | 0 | 1 | – |
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2009-04-25 | HailRed Desert, Sweetwater County | 1.75 in hail | 0 | 0 | $963K |
| 2021-07-28 | Flash FloodBlairtown, Sweetwater County | 0 | 0 | $817K | |
| 2002-04-13 | WildfireSuperior, Sweetwater County | 0 | 0 | $428K | |
| 2007-08-17 | Flash FloodGreen River, Sweetwater County | 0 | 0 | $356K | |
| 2015-07-07 | Flash FloodBlairtown, Sweetwater County | 0 | 0 | $311K | |
| 2000-04-14 | TornadoJames Town, Sweetwater County | F1 0.5 mi x 50 yd | 0 | 0 | $51K |
| 2025-12-10 | High WindSweetwater County · forecast zone Rock Springs & Green River | 43 kt wind | 0 | 0 | $10K |
| 2017-05-26 | TornadoTable Rock, Sweetwater County | EF0 11.36 mi x 30 yd | 0 | 0 | $1K |
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 $25K, in the dollars of the day) holds: June 27, 1974 (tornado, Sweetwater 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 Sweetwater 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 |
|---|---|---|---|---|---|---|---|---|
| High wind and dust storms | – | – | – | – | 4 | 66 | 203 z | 109 |
| Winter storms | – | – | – | – | 21 | 61 | 101 | 43 |
| Severe thunderstorm wind | 1 | 3 | 7 | 6 | 17 | 26 | 21 | 43 |
| Extreme cold | – | – | – | – | 2 | 0 | 12 | 19 |
| Tornadoes | 0 | 1 | 6 | 3 | 6 | 3 | 5 | 2 |
| Fog, smoke and funnel clouds | – | – | – | – | 6 | 14 | 2 | 0 |
High wind and dust storms in the 2010s: 203 records against 66 in the decade before, 203 of them forecast-zone records. Cells marked z rose mostly through zone records. The local National Weather Service office files these once per forecast zone, so a change in how it draws its zones or splits a storm into records moves this count as much as the weather does; read it beside the Sweetwater County days with a record above.
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 Sweetwater County. The two busiest months are in violet.
The values, month by month
Jan 109 · Feb 109 · Mar 98 · Apr 65 · May 57 · Jun 70 · Jul 47 · Aug 38 · Sep 37 · Oct 48 · Nov 70 · Dec 116 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began.
Federal disaster declarations for Sweetwater County
FEMA's register lists 4 declarations that include Sweetwater County: 2 major disasters, 2 emergencies and 0 fire management assistance declarations. Most were for biological (2) and severe storm (1).
| Declared | Number | Type | Title |
|---|---|---|---|
| 2020-04-11 | DR-4535 | Biological | Covid-19 Pandemic |
| 2020-03-13 | EM-3479 | Biological | Covid-19 |
| 2011-07-22 | DR-4007 | Severe Storm | Severe Storms, Flooding, and Landslides |
| 1977-06-15 | EM-3043 | 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.
How many floods has Sweetwater County had?
NOAA's Storm Events Database holds 12 flood or flash flood records for Sweetwater County from 1998 to 2024, on 12 days, with 0 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Sweetwater County ranks 2061st of 2,942 U.S. counties.
The National Flood Insurance Program has paid $901,000 on 22 claims filed in Sweetwater County; the most in one year was 6 in 1989. Claims count insured losses only: uninsured flood damage is not in this file.
The values, year by year
1980: 1 · 1981: 1 · 1985: 1 · 1989: 6 · 1991: 3 · 1993: 1 · 1996: 2 · 2004: 1 · 2008: 1 · 2009: 1 · 2015: 3 · 2017: 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 Sweetwater County
FEMA's National Risk Index rates Sweetwater County Very Low overall, with an expected annual loss of $11.6 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 |
|---|---|---|---|
| Winter Weather | Relatively High | $339K | 13 a year (modeled) |
| Landslide | Relatively Moderate | $71K | 2.6 a year (modeled) |
| Wildfire | Relatively Low | $151K | once in about 1,526 years (modeled) |
| Earthquake | Relatively Low | $728K | once in about 272 years (modeled) |
| Cold Wave | Relatively Low | $1.5M | 1.2 a year (modeled) |
| Lightning | Relatively Low | $337K | 39 a year (modeled) |
| Riverine Flooding | Relatively Low | $8.2M | once in about 3 years (modeled) |
| Drought | Very Low | $4K | 120 modeled event-days a year |
Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.
Counties that share a border with Sweetwater 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 WyomingEvery Wyoming tornado since 1950 and the counties with the most per square mile
- High wind and dust storms in WyomingThe state's high wind and dust records, by county, year and month
- The Wyoming recordEvery hazard in the state, its deadliest events and its federal declarations
- FEMA's risk rating for each hazard in Sweetwater CountyThe hazard risk calculator: 18 hazards beside the county's record
- Download Sweetwater County's FEMA declarations (CSV)4 rows: every declaration that named the county, for your own analysis