Granite County, Montana: Natural Disaster Risk and History
Granite County, Montana has a Very Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 9.4 out of 100, higher than about 9% of US counties, with landslides, wildfires and avalanches scoring highest of its 18 hazards and $4.2 million a year in expected losses.
OpenFEMA lists 6 federal disaster declarations that included Granite County since 1981, not counting 2 for COVID-19; the latest is DR-1996-MT (Severe Storms and Flooding, declared 17 June 2011). NOAA's Storm Prediction Center recorded 2 tornadoes touching Granite County from 1950 to 2025.
Live weather alerts for Montana All official warnings Latest FEMA declarations
Population 3,291 Buildings worth $1.5 billion Area 1,750 sq mi Risk rank in Montana 40 of 56 FIPS 30039
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Landslide | Relatively Moderate | 91.9 | $67,999 | about 1.2 a year | — |
| Wildfire | Relatively Low | 88.6 | $1.0 million | about once every 180 years | — |
| Avalanche | Relatively High | 86.3 | $1.0 million | about once every 5.0 years | 6 |
| Winter weather | Relatively Low | 48.8 | $56,144 | about 53 a year | 999 |
| Earthquake | Very Low | 37.7 | $119,962 | about once every 185 years | — |
| Cold wave | Relatively Low | 34.4 | $470,376 | about 2.9 a year | 56 |
| Ice storm | Relatively Low | 29.1 | $27,487 | about once every 7.0 years | 10 |
| Drought | Very Low | 17.0 | $1,646 | about 47 a year | 1,379 |
| Inland flooding | Very Low | 11.1 | $1.3 million | about once every 3.5 years | 8 |
| Lightning | Very Low | 8.2 | $24,360 | about 28 a year | 26,626 strikes |
| Hail | Very Low | 6.5 | $16,846 | about once every 1.7 years | 23 |
| Heat wave | Very Low | 4.2 | $3,825 | about once every 2.6 years | 6.8 |
| Strong wind | Very Low | 3.2 | $15,215 | about once every 3.5 years | 11 |
| Tornado | Very Low | 2.7 | $5,325 | about once every 34 years | 1 |
| Coastal flooding | Not Applicable | — | — | — | — |
| Hurricane | Not Applicable | — | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic activity | Not Applicable | — | — | — | — |
Score: FEMA's percentile among US counties that face the hazard (higher = more risk). Expected loss: FEMA's modelled average yearly loss to buildings, people (as a statistical value) and crops. How often: FEMA's annualised frequency of the hazard in the county; for some hazards it counts event-days, so it is a rough guide, not a forecast. "Not Applicable" means FEMA does not model that hazard here.
Federal disaster declarations 6
Most common: Fire 2, Flood 2, Severe Storm 1, Hurricane 1.
| Decade | Declarations | Incident types |
|---|---|---|
| 1980s | 2 | Flood ×2 |
| 2000s | 3 | Fire ×2, Hurricane |
| 2010s | 1 | Severe Storm |
The last 6
Widest declarations that included Granite County
- Hurricane Katrina Evacuation (2005, EM-3253-MT): 56 Montana counties designated.
- Severe Storms and Flooding (2011, DR-1996-MT): 49 Montana counties designated.
- Wildfires (2000, DR-1340-MT): 48 Montana counties designated.
Named storms in its declarations: Hurricane Katrina (2005).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. Montana also had 18 statewide declarations with no county list.
Tornado record since 1950 2
| Tornadoes touching the county | 2 |
|---|---|
| Strongest-rated | (E)F0 ×2 |
| Peak month | May (1) |
| Deadliest | — |
| Longest path | 11 Aug 1988, F0, 2 mi path |
| Most recent | 11 Aug 1988, F0, 2 mi path |
| Deaths / injuries on those paths | 0 / 0 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 2 | 0 | 0 | 0 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0 |
Deaths and injuries are for each tornado's whole path, which can run beyond this county. F-scale ratings before February 2007, Enhanced Fujita (EF) after.
How Granite County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Granite County (this page) | — | Very Low | 9.4 | Landslide |
| Deer Lodge County | 48 km | Very Low | 17.6 | Avalanche |
| Ravalli County | 63 km | Relatively Low | 78.5 | Wildfire |
| Powell County | 63 km | Very Low | 10.0 | Landslide |
| Missoula County | 79 km | Relatively Low | 77.0 | Wildfire |
| Silver Bow County | 82 km | Very Low | 38.0 | Winter weather |
Nearest by distance between county centres. Every county in Montana, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively Moderate 49.6 |
|---|---|
| Community resilience | Relatively Low 29.9 |
| Community risk factor | 1.14 |
| Expected annual loss, all hazards | $4.2 million |
FEMA scales expected losses up where social vulnerability is high (people who may find it harder to prepare, evacuate or recover) and down where community resilience is high. A factor above 1 raises the risk score. For social vulnerability a high rating is worse; for resilience a high rating is better.
Prepare for Granite County's main hazards
- Right now: National Weather Service alerts for Montana · all official warnings on Global Incident Tracker.
- Landslide: Landslides recorded
- Wildfire: US wildfires now · Wildfire smoke: what protects you
- Avalanche: Official warnings now
- Your property's flood zone: FEMA Flood Map Service Center ↗ — this page cannot tell you that.
- Official preparedness guidance: Ready.gov ↗ and your county emergency management office.
What this page shows, and what it misses
FEMA's National Risk Index rates a whole county against every other US county; it is a planning-level estimate for nationwide comparison, not a flood-zone map and not a substitute for a local risk assessment or the risk to one home. Declarations are presidential disaster, emergency and fire management declarations that named this county; state declarations and SBA or USDA designations are not included. Tornadoes are counted when the county is one of up to four listed on the track; 670 tornadoes that crossed a state line carry no county list in NOAA's file and are left out.
Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties - v1.20.0 (December 2025). Retrieved from https://services.arcgis.com/XG15cJAlne2vxtgt/ArcGIS/rest/services/National_Risk_Index_Counties/FeatureServer/0/query on November 2, 2026, 1:20 PM EST. This product uses the Federal Emergency Management Agency’s National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Federal Emergency Management Agency (FEMA), OpenFEMA Dataset: Disaster Declarations Summaries - v2, retrieved from https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries on November 2, 2026, 1:21 PM EST. This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Tornado records: NOAA/NWS Storm Prediction Center, Severe Weather Database, tornadoes 1950–2025 (https://www.spc.noaa.gov/wcm/data/1950-2025_actual_tornadoes.csv, downloaded 2 November 2026). Public domain; not endorsed by NOAA. Compiled by Global Incident Tracker.
Questions about Granite County
What natural disasters is Granite County, Montana most at risk from?
Granite County, Montana has a Very Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 9.4 out of 100, higher than about 9% of US counties, with landslides, wildfires and avalanches scoring highest of its 18 hazards and $4.2 million a year in expected losses.
How many federal disaster declarations has Granite County had?
OpenFEMA lists 6 federal disaster declarations that included Granite County since 1981, not counting 2 for COVID-19; the latest is DR-1996-MT (Severe Storms and Flooding, declared 17 June 2011). Another 18 Montana declarations were made statewide without a county list.
How many tornadoes have hit Granite County?
NOAA's Storm Prediction Center recorded 2 tornadoes touching Granite County from 1950 to 2025.
Is the National Risk Index a flood zone map?
No. The National Risk Index is a planning-level estimate for a whole county, built for nationwide comparison. It does not tell you the flood zone or the risk of a single property: for that, look up the address on FEMA's Flood Map Service Center (msc.fema.gov) and ask your local floodplain manager.