Owyhee County, Idaho
County storm and disaster record · FIPS 16073 · population 11,869 · 7,668 sq mi
NOAA's Storm Events Database holds 365 records for Owyhee County, Idaho from 1950 through June 30, 2026, on 249 days; the most frequent are winter storm records (163 records). 249 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 September 6, 2022 excessive heat, filed for the forecast zone Lower Treasure Valley, which covers the county: 1 death. FEMA has issued 6 declarations naming the county since 1964, 4 of them for natural hazards; the latest for a natural hazard was “Severe Storms and Flooding” on February 27, 2006.
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
- 365on 249 days, 1950 to June 30, 2026
- Deaths recorded
- 417 injuries
- Damage, 2025 dollars
- $129Mas filed (scale steps before 1993)
- Tornadoes
- 5strongest EF0
- FEMA declarations
- 6latest 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 Owyhee County most?
The most frequent records are winter storm records: 163 since 1996. 58% of its winter storm records since 1996 fell in December and January. The rank column places the county among Idaho'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 | 163 | 106 | 1996-2025 | 1 | 11 | $120M | 44 of 44 |
| High wind and dust storms | 64 | 40 | 1996-2026 | 0 | 0 | $141K | 42 of 44 |
| Severe thunderstorm wind | 43 | 35 | 1959-2026 | 0 | 4 | $301K | 44 of 44 |
| Floods | 28 | 25 | 1996-2023 | 1 | 0 | – | 43 of 44 |
| Hail | 27 | 23 | 1989-2022 | 0 | 0 | – | 43 of 44 |
| Heavy rain | 14 | 9 | 1996-2024 | 0 | 0 | $19K | 33 of 44 |
| Fog, smoke and funnel clouds | 9 | 7 | 1997-2019 | 0 | 1 | – | 37 of 44 |
| Wildfires | 8 | 7 | 1997-2015 | 1 | 0 | $7.7M | 36 of 44 |
| Tornadoes | 5 | 5 | 1998-2023 | 0 | 1 | $54K | 36 of 44 |
| Extreme cold | 3 | 2 | 2002-2012 | 0 | 0 | – | 41 of 44 |
| Heat | 1 | 1 | 2022-2022 | 1 | 0 | – | 32 of 44 |
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 Owyhee County had?
NOAA records 5 tornadoes in Owyhee County from 1998 to 2023, the strongest rated EF0, with 0 deaths and 1 injury 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 5 tornadoes whose track touched Owyhee County since 1950 (NOAA's county records number 5, the same count); along their whole tracks they killed 0 people.
Map of the strongest tornado tracks in Idaho.
Every tornado record filed for Owyhee County (5)
| Date | Place | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2023-05-27 | Grandview, Owyhee County | EF0 5.04 mi x 3 yd | 0 | 0 | – |
| 2022-05-27 | Givens Hot Spgs, Owyhee County | EF0 3.77 mi x 35 yd | 0 | 0 | – |
| 2009-06-21 | Riddle, Owyhee County | EF0 0.12 mi x 20 yd | 0 | 0 | – |
| 1998-07-10 | Oreana, Owyhee County | F0 0.2 mi x 50 yd | 0 | 1 | $54K |
| 1998-04-23 | Bruneau, Owyhee County | F0 0.5 mi x 50 yd | 0 | 0 | – |
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 Owyhee County?
The most recent record with damage, injuries or deaths is the January 18, 2023 heavy snow (7 injuries).
The Ada County Sheriff attributed 48 total traffic accidents to the snowfall and resulting slippery road conditions.
National Weather Service event narrative, NOAA Storm Events Database (search the full record, event 1075967)
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2026-05-28 | Thunderstorm WindMarsing, Owyhee County | 51 kt wind | 0 | 0 | – |
| 2026-05-13 | High WindAda County and 2 more · forecast zone Upper Treasure Valley | 53 kt wind | 0 | 0 | – |
| 2026-05-13 | High WindAda County and 2 more · forecast zone Upper Treasure Valley | 56 kt wind | 0 | 0 | – |
| 2025-12-17 | High WindAda County and 2 more · forecast zone Upper Treasure Valley | 57 kt wind | 0 | 0 | – |
| 2025-12-17 | High WindOwyhee County · forecast zone Owyhee Mountains | 53 kt wind | 0 | 0 | – |
| 2025-05-11 | Thunderstorm WindHot Spg, Owyhee County | 55 kt wind | 0 | 0 | – |
| 2025-03-16 | High WindOwyhee County · forecast zone Southwest Highlands | 53 kt wind | 0 | 0 | – |
| 2025-02-13 | Winter WeatherCanyon County and 4 more · forecast zone Lower Treasure Valley | 0 | 0 | – | |
| 2025-02-06 | Winter WeatherCanyon County and 4 more · forecast zone Lower Treasure Valley | 0 | 0 | – | |
| 2025-02-02 | Winter WeatherAda County and 2 more · forecast zone Upper Treasure Valley | 0 | 0 | – | |
| 2023-05-27 | TornadoGrandview, Owyhee County | EF0 5.04 mi x 3 yd | 0 | 0 | – |
| 2023-01-18 | Heavy SnowAda County and 2 more · forecast zone Upper Treasure Valley | 0 | 7 | – |
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 |
|---|---|---|---|---|---|
| 2022-09-06 | Excessive HeatCanyon County and 4 more · forecast zone Lower Treasure Valley Multiple newspapers reported on an infant that died after being left in a hot car in New Plymouth, Idaho on September 6th. | 1 | 0 | – | |
| 2013-12-07 | Heavy SnowCanyon County and 4 more · forecast zone Lower Treasure Valley Reports of 5 to 6 inches were received via social media. A traffic accident attributed to slick roads resulted in one fatality on Interstate 84, 2 miles east of Caldwell. | 1 | 0 | – | |
| 2009-06-06 | Flash FloodMurphy, Owyhee County Flash Flooding was reported by law enforcement along Highway 78 and closed a section from Grandview to Walters Ferry, Idaho. A fatality occured when a vehicle was swept into the Snake River near Murphy, Idaho. | 1 | 0 | – | |
| 2008-08-25 | WildfireAda County and 2 more · forecast zone Upper Treasure Valley A wildfire in Southeast Boise caused by an electrical component near an Idaho Power sub station quickly burned out of control destroying 10 homes and damaging many more including 1 fatality. Another wildfire near Mountain Home burned around 500 acres. | 1 | 0 | $6.9M | |
| 2023-01-18 | Heavy SnowAda County and 2 more · forecast zone Upper Treasure Valley The Ada County Sheriff attributed 48 total traffic accidents to the snowfall and resulting slippery road conditions. | 0 | 7 | – | |
| 2001-11-28 | Heavy SnowCanyon County and 4 more · forecast zone Lower Treasure Valley A very moist Pacific storm brought the first major snowfall to the Treasure and Magic Valleys. Snow began falling around noon and continued until the next morning. Over one hundred slide-offs and motor vehicle collisions occurred along Interstate 84 from Oregon-Idaho state line east to Twin Falls. Traffic was brought ... | 0 | 4 | – | |
| 1993-05-03 | Thunderstorm WindOwyhee County Severe thunderstorm winds uprooted trees and tore the roofs off some buildings in Gem County. Four persons sustained minor injuries when the roof came off a mobile home along State Highway 52, 25 miles northwest of Boise. Heavy rain damaged the household contents. Thunderstorm winds in Owyhee County lifted 10-inch ... | 0 | 4 | $102K | |
| 2013-02-05 | Dense FogAda County and 2 more · forecast zone Upper Treasure Valley Numerous reports of slide offs, roll overs and crashes due to dense fog and freezing rain in the area. | 0 | 1 | – |
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2017-01-18 | Heavy SnowCanyon County and 4 more · forecast zone Lower Treasure Valley | 0 | 0 | $120M | |
| 2008-08-25 | WildfireAda County and 2 more · forecast zone Upper Treasure Valley | 1 | 0 | $6.9M | |
| 2010-07-28 | WildfireAda County and 2 more · forecast zone Upper Treasure Valley | 0 | 0 | $677K | |
| 1993-05-03 | Thunderstorm WindOwyhee County | 0 | 4 | $102K | |
| 1998-07-10 | TornadoOreana, Owyhee County | F0 0.2 mi x 50 yd | 0 | 1 | $54K |
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 Owyhee 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 | – | – | – | – | 38 | 36 | 35 | 54 |
| High wind and dust storms | – | – | – | – | 6 | 22 | 10 | 26 |
| Severe thunderstorm wind | 1 | 0 | 3 | 3 | 13 | 8 | 6 | 9 |
| Floods | – | – | – | – | 12 | 8 | 6 | 2 |
| Hail | 0 | 0 | 0 | 1 | 14 | 6 | 3 | 3 |
| Heavy rain | – | – | – | – | 3 | 0 | 0 | 11 |
Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).
What time of year?
58% of its winter storm records since 1996 fell in December and January. The two busiest months are in violet.
The values, month by month
Jan 49 · Feb 35 · Mar 36 · Apr 23 · May 34 · Jun 35 · Jul 27 · Aug 33 · Sep 8 · Oct 7 · Nov 19 · Dec 59 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began.
Federal disaster declarations for Owyhee County
FEMA's register lists 6 declarations that include Owyhee County: 4 major disasters, 2 emergencies and 0 fire management assistance declarations. Most were for biological (2) and severe storm (2).
| Declared | Number | Type | Title |
|---|---|---|---|
| 2020-04-09 | DR-4534 | Biological | Covid-19 Pandemic |
| 2020-03-13 | EM-3467 | Biological | Covid-19 |
| 2006-02-27 | DR-1630 | Severe Storm | Severe Storms and Flooding |
| 2005-09-13 | EM-3244 | Hurricane | Hurricane Katrina |
| 1997-01-04 | DR-1154 | Severe Storm | Severe Storms, Flooding, Mud and Landslides |
| 1964-12-31 | DR-186 | Flood | Heavy Rains & 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.
FEMA's modeled risk for Owyhee County
FEMA's National Risk Index rates Owyhee County Relatively Low overall, with an expected annual loss of $8.5 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 Moderate | $2.7M | once in about 61 years (modeled) |
| Winter Weather | Relatively Moderate | $83K | 12 a year (modeled) |
| Avalanche | Relatively Low | $4K | once in about 100 years (modeled) |
| Landslide | Relatively Low | $4K | 1.6 a year (modeled) |
| Riverine Flooding | Relatively Low | $5.2M | about once a year (modeled) |
| Heat Wave | Relatively Low | $208K | 2.9 modeled event-days a year |
| Volcanic Activity | Very Low | $5 | once in about 3,333 years (modeled) |
| Earthquake | Very Low | $65K | once in about 429 years (modeled) |
Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.
Counties that share a border with Owyhee 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 IdahoEvery Idaho tornado since 1950 and the counties with the most per square mile
- Winter storms in IdahoThe state's winter storm records, by county, year and month
- The Idaho recordEvery hazard in the state, its deadliest events and its federal declarations
- FEMA's risk rating for each hazard in Owyhee CountyThe hazard risk calculator: 18 hazards beside the county's record
- Download Owyhee County's FEMA declarations (CSV)6 rows: every declaration that named the county, for your own analysis