Sweet Grass County, Montana
Natural disaster risk, federal disaster history and flood insurance facts.
Sweet Grass County, Montana has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 92% of US counties. It ranks 41st of 56 counties in Montana. The costliest hazards here are inland flooding, wildfires and cold waves. FEMA estimates about $5.9 million a year in expected losses, or roughly $1,604 per resident. Since 1997 it has been included in 8 federal disaster or emergency declarations for natural events (5 major disasters). The most recent was in April 2026 (severe winter storm and straight-line winds). Only 14 homes here carry federal flood insurance. Since 1978, federal flood insurance has paid about $419,000 on 10 claims here.
FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.
Top risks in Sweet Grass County
- Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
- Price a flood policy now. Most new federal policies take 30 days to start.
- Clear dry plants and debris within 5 feet of the house.
- Get home insurance quotes early; availability varies by area.
- Insulate pipes in outside walls, crawl spaces and garages.
- Know how to shut off the main water valve.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Inland flooding | 19.7 | $3M | ||
| Wildfire | 88.1 | $1M | ||
| Cold wave | 29.8 | $578K | ||
| Earthquake | 34.9 | $157K | ||
| Hail | 21.4 | $109K | ||
| Lightning | 18.3 | $88K | ||
| Winter weather | 32.1 | $46K | ||
| Strong wind | 3.3 | $25K | ||
| Tornado | 3.8 | $16K | ||
| Heat wave | 6.6 | $13K | ||
| Drought | 18.2 | $4K | ||
| Landslide | 56.3 | $3K | ||
| Ice storm | 4.0 | $2K | ||
| Avalanche | 60.7 | $2K |
Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is very low and community resilience is relatively moderate in FEMA's measures.
Federal disaster history
Recent disasters nationwide ›Declarations by decade
Federal declarations for natural events that included Sweet Grass County. 2020s bar runs to November 2026.
By type
Most recent
Montana also had 36 statewide declarations that did not name single counties.
Storm history since 1955
Tornado risk by county ›The National Weather Service has logged 199 storm reports in Sweet Grass County since 1955 and about $4.5 million in reported damage. The strongest on record here was an F1 tornado on August 22, 1965.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| Aug 22, 1965 | F1 | – | 0 / 0 |
| May 20, 1973 | F0 | – | 0 / 0 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| May 20, 2011 | Flood | Melville | $4M |
| Jul 9, 1994 | Thunderstorm Wind | Big Timber | $500K |
| May 20, 1973 | Tornado | – | $30 |
Source: NOAA Storm Events Database, county-based reports through Jul 28, 2026. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.
Flood insurance in Sweet Grass County
Check your address flood zone ›National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.
Homes in Sweet Grass County
Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 1,900 housing units.
Compare in Montana
All 56 ›| Largest counties | Overall risk | Top hazard |
|---|---|---|
| Yellowstone County | Inland flooding | |
| Gallatin County | Earthquake | |
| Missoula County | Inland flooding | |
| Flathead County | Inland flooding | |
| Cascade County | Inland flooding | |
| Lewis and Clark County | Cold wave | |
| Ravalli County | Wildfire | |
| Silver Bow County | Cold wave |
Neighboring counties
| County | Overall risk | Declarations |
|---|---|---|
| Park County | 12 | |
| Stillwater County | 14 | |
| Wheatland County | 8 | |
| Meagher County | 8 | |
| Golden Valley County | 8 |
Common questions about Sweet Grass County
What is the biggest natural hazard in Sweet Grass County?
Inland flooding has the highest expected yearly losses in Sweet Grass County, about $3.4 million a year in FEMA's estimate. Wildfire is second at $1.5 million.
How many federal disasters has Sweet Grass County had?
Sweet Grass County has been included in 8 federal disaster or emergency declarations for natural events since 1997, including 5 major disasters. The most recent was Severe Winter Storm and Straight-Line Winds in April 2026.
Is Sweet Grass County a high-risk place to live?
Its overall rating is Very Low, 41st highest of 56 in Montana. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.
Do I need flood insurance in Sweet Grass County?
Standard home insurance does not cover flooding. About 1 in 250 homes in Sweet Grass County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.
How many tornadoes has Sweet Grass County had?
NOAA records list 2 tornadoes in Sweet Grass County since 1950. The strongest was an F1 tornado on August 22, 1965. The weather service has also logged 130 hail reports and 10 floods here.
Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.