Granite County, Montana severe weather history spans 57 recorded events between 1958 and 2025. The dominant hazard is hail, accounting for 54.4% of all recorded events. It ranks #3,025 nationally and #54 in Montana.
57
Recorded events
0
Direct deaths
0
Direct injuries
$70K
Property damage
The record
What the Granite County, Montana severe weather history record shows
Across the archive, Granite County, Montana severe weather history averages 0.9 recorded events a year. The busiest stretch on record is the 2000s, with 18 events logged in that decade alone. Roughly 9 events fall before 1990 and 48 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The costliest is flood, with $50K in reported property damage. In total, 7 distinct hazard types appear in this county archive, each listed with its own dated record below.
By hazard type
Every hazard type recorded in Granite County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Hail | 31 | 0 | $12K | 2 | 1958–2022 |
| Thunderstorm Wind | 15 | 0 | $0 | 60 | 1966–2025 |
| Flash Flood | 3 | 0 | $7K | 0 | 2010–2013 |
| Flood | 3 | 0 | $50K | 0 | 2011–2018 |
| Tornado | 2 | 0 | $0 | F0 | 1971–1988 |
| Heavy Rain | 2 | 0 | $1K | 0 | 2008–2014 |
| Debris Flow | 1 | 0 | $0 | 0 | 2023–2023 |
Decade by decade
Granite County, Montana severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
1 mapped tornado paths intersect this county: 1 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 |
|---|---|---|---|---|---|
| 1988-08-11 | EF0 | 0 | 0 | 2.0 mi | Touched down here |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Granite county saw widespread impacts from the heavy rain. Philipsburg, MT received 3.28 inches of rain in 24 hours from noon 6/12 through noon 6/13. A public report from Georgetown Lake, MT had a measured 3.7 inches of rain over the 2-day event. Fred Burr Creek was particularly hard hit, with private driveway bridges being washed out, thus stranding a couple residents. Many of these same residents had basement flooding as well. USGS stream gauges on Boulder Creek near Maxville recorded 1410 cfs; 1000 cfs begins to cause road flooding issues, and this was much above this impact level. Rock Creek and Flint Creek both saw extremely rapid and high flows, with water spilling into adjacent fields. Georgetown Lake over-topped its spillway for the first time in years. Sapphire Mountain ditch managers narrowly avoided damage to a major irrigation channel feeding the Bitterroot Valley.
A slow moving wet thunderstorm dumped at least 1 of rainfall in one hour just southeast of Drummond. A rancher experienced a 5 foot wall of fast moving water that moved down their driveway. The fast flowing water laden with pea-sized hail and mud severely damaged grain & alfalfa crops, irrigation sprinklers and a fence. They said it was the worst flooding in at least 20 years.
A slow moving thunderstorm produced over an inch of rain in less than one hour during the evening of August 9, 2013 over the terrain southeast of Drummond, Montana. This triggered a flash flood up to four feet high that moved from small hillside gulches located north of Interstate 90 over the highway. One vehicle slid off the road and I-90 was shut down for a period of time until the water levels subsided.
Context
Risk, population and federal disasters
Very Low
FEMA NRI risk rating
3,462
Population (ACS)
$353K
Median home value
8
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| 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 |
| Aug 30, 2000 | Fire | WILDFIRES | DR |
| Aug 5, 2000 | Fire | MT-SOUTHWESTERN ZONE TWO FIRE COMPLEX | FM |
Quick answers
Frequently asked
How many severe weather events have been recorded in Granite County, Montana?
57 events are on record between 1958 and 2025, causing 0 direct deaths and $70K in property damage.
What is the most common severe weather hazard in Granite County?
Hail, with 31 recorded events — 54.4% of everything in the archive for this county.
How many tornadoes have crossed Granite County?
1 mapped tornado paths intersect the county boundary; 1 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover Granite County?
8 federal disaster declarations from FEMA include Granite County, each tied to a specific incident period.
How risky is Granite County compared with the rest of the country?
FEMA's National Risk Index rates Granite County as very low risk, placing it in the 9 percentile of its state for expected annual loss.
Where does the Granite 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
- Golden Valley County 156
- Hill County 343
- Glacier County 171
- Jefferson County 102
- Garfield County 619
- Judith Basin County 247
Cite this page
“Granite County, Montana.” Severe Weather History. severeweatherhistory.com/county/montana/granite-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.