Big Horn County, Montana severe weather history spans 439 recorded events between 1956 and 2025. The dominant hazard is hail, accounting for 56.3% of all recorded events. It ranks #1,104 nationally and #15 in Montana.
439
Recorded events
6
Direct deaths
9
Direct injuries
$4.7M
Property damage
The record
What the Big Horn County, Montana severe weather history record shows
Across the archive, Big Horn County, Montana severe weather history averages 6.4 recorded events a year. The busiest stretch on record is the 2000s, with 164 events logged in that decade alone. Roughly 29 events fall before 1990 and 410 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the Big Horn County, Montana record is thunderstorm wind, responsible for 4 direct deaths. The costliest is flood, with $4.0M in reported property damage. In total, 9 distinct hazard types appear in this county archive, each listed with its own dated record below.
By hazard type
Every hazard type recorded in Big Horn County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Hail | 247 | 0 | $115K | 4 | 1956–2025 |
| Thunderstorm Wind | 148 | 4 | $22K | 100 | 1970–2025 |
| Flash Flood | 13 | 1 | $0 | 0 | 1997–2023 |
| Flood | 11 | 0 | $4.0M | 0 | 2011–2019 |
| Tornado | 10 | 0 | $525K | F1 | 1965–2018 |
| Heavy Rain | 5 | 0 | $0 | 0 | 2005–2007 |
| Funnel Cloud | 3 | 0 | $0 | 0 | 2001–2010 |
| Lightning | 1 | 1 | $0 | 0 | 1999–1999 |
| Wildfire | 1 | 0 | $0 | 0 | 2001–2001 |
Decade by decade
Big Horn County, Montana severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
12 mapped tornado paths intersect this county: 12 touched down inside it and 0 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 2018-06-07 | EF1 | 0 | 0 | 0.8 mi | Touched down here |
| 1996-06-22 | EF1 | 0 | 0 | 4.0 mi | Touched down here |
| 1991-06-21 | EF1 | 0 | 0 | 0.2 mi | Touched down here |
| 1991-07-09 | EF1 | 0 | 0 | 0.1 mi | Touched down here |
| 1984-06-21 | EF1 | 0 | 0 | 1.0 mi | Touched down here |
| 1984-06-21 | EF1 | 0 | 0 | 2.0 mi | Touched down here |
| 1998-08-23 | EF0 | 0 | 0 | 7.0 mi | Touched down here |
| 1996-05-13 | EF0 | 0 | 0 | 0.1 mi | Touched down here |
| 1995-05-11 | EF0 | 0 | 0 | 0.1 mi | Touched down here |
| 1978-06-24 | EF0 | 0 | 0 | 0.1 mi | Touched down here |
Significant events
Deadliest events on record in Big Horn County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Jul 17, 2008 | Thunderstorm Wind | DECKER | 2 | 0 | $0 |
| Jul 15, 2022 | Thunderstorm Wind | HARDIN | 1 | 6 | $0 |
| Aug 17, 2021 | Thunderstorm Wind | CROW AGENCY | 1 | 0 | $0 |
| May 24, 2011 | Flash Flood | ST XAVIER | 1 | 0 | $0 |
| Jul 18, 1999 | Lightning | DECKER | 1 | 0 | $0 |
| Sep 18, 1989 | Thunderstorm Wind | 0 | 3 | $0 |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Two fatalities, both drownings, occurred from a severe thunderstorm that moved across the Tongue River Reservoir. A man fell from a dock and a woman drowned when her small boat capsized as a result of very strong thunderstorm winds.
Around 4:15 PM MDT, a thunderstorm outflow moved through the Hardin area. It produced a wind gust of 62 mph in the 4:35 PM MDT observations from the Big Horn County Airport. Along with the outflow winds, blowing dust reduced visibility to less than a quarter mile on the AWOS. This resulted in a 20 to 30 vehicle pile up along Interstate 90 around mile marker 493 reported at 4:30 PM MDT, very close to the airport. Prior to this, the Montana DOT RWIS station at Arrow Creek Hill, 25 miles west of Hardin, reported a peak wind gust of 48 mph about 15 minutes prior. This accident resulted in 6 deaths and multiple injuries.
A strong thunderstorm outflow passed over Crow Agency around 630pm with winds to 55 mph. A couple hours later, a shower with up to 20dbz moved over Crow Agency around 830pm, producing winds to 64 mph across a small area. A roof blew off an arbor, throwing it across the street, striking a camper in the head and throat.
Context
Risk, population and federal disasters
Relatively Low
FEMA NRI risk rating
12,891
Population (ACS)
$143K
Median home value
9
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| Apr 7, 2026 | Straight-Line Winds | SEVERE WINTER STORM AND STRAIGHT-LINE WINDS | DR |
| Jul 28, 2021 | Fire | PF FIRE | FM |
| Mar 31, 2020 | Biological | COVID-19 PANDEMIC | DR |
| Mar 13, 2020 | Biological | COVID-19 | EM |
| Jun 17, 2011 | Severe Storm | SEVERE STORMS AND FLOODING | DR |
| Sep 13, 2005 | Hurricane | HURRICANE KATRINA EVACUATION | EM |
Within the county
Most affected places
- Hardin 128
Quick answers
Frequently asked
How many severe weather events have been recorded in Big Horn County, Montana?
439 events are on record between 1956 and 2025, causing 6 direct deaths and $4.7M in property damage.
What is the most common severe weather hazard in Big Horn County?
Hail, with 247 recorded events — 56.3% of everything in the archive for this county.
How many tornadoes have crossed Big Horn County?
12 mapped tornado paths intersect the county boundary; 12 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover Big Horn County?
9 federal disaster declarations from FEMA include Big Horn County, each tied to a specific incident period.
How risky is Big Horn County compared with the rest of the country?
FEMA's National Risk Index rates Big Horn County as relatively low risk, placing it in the 57 percentile of its state for expected annual loss.
Where does the Big Horn County, Montana severe weather history data come from?
Every figure is drawn from United States federal public-domain records: NOAA/NCEI Storm Events for the event archive, NOAA SPC SVRGIS for mapped tornado paths, FEMA for disaster declarations and risk ratings, and the U.S. Census for population context. Dates are shown in UTC and recent entries may still be revised by NOAA.
Nearby
Neighbouring counties
- Beaverhead County 196
- Blaine County 252
- Broadwater County 80
- Carbon County 191
- Carter County 457
- Cascade County 620
Cite this page
“Big Horn County, Montana.” Severe Weather History. severeweatherhistory.com/county/montana/big-horn-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.