Home › Montana › Sweet Grass County

Sweet Grass County, Montana

Natural disaster risk, federal disaster history and flood insurance facts.

Very Low overall risk
41st of 56highest risk in Montana
$6Mexpected losses a year
8federal declarations
1 in 250homes with flood insurance
Photo: U.S. Geological Survey, public domain

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

$3.4 million a yearExpected losses. Damaging events about once every 3 years.
  • 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.
$1.5 million a yearExpected losses. Damaging events about once every 805 years.
  • Clear dry plants and debris within 5 feet of the house.
  • Get home insurance quotes early; availability varies by area.
$577,849 a yearExpected losses. Damaging events about 2 times a year.
  • Insulate pipes in outside walls, crawl spaces and garages.
  • Know how to shut off the main water valve.
HazardRatingScoreExpected loss a year
Inland floodingVery Low19.7
$3M
WildfireLow88.1
$1M
Cold waveLow29.8
$578K
EarthquakeVery Low34.9
$157K
HailVery Low21.4
$109K
LightningVery Low18.3
$88K
Winter weatherLow32.1
$46K
Strong windVery Low3.3
$25K
TornadoVery Low3.8
$16K
Heat waveVery Low6.6
$13K
DroughtVery Low18.2
$4K
LandslideVery Low56.3
$3K
Ice stormVery Low4.0
$2K
AvalancheVery Low60.7
$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

Fire3
Severe Storm2
Hurricane1
Flood1
Straight-Line Winds1

Most recent

Apr 7, 2026Severe Winter Storm and Straight-Line WindsMajor disaster
Jun 16, 2022Severe Storm and FloodingMajor disaster
Jun 17, 2011Severe Storms and FloodingMajor disaster
Aug 30, 2006Derby FireFire management
Sep 13, 2005Hurricane Katrina EvacuationEmergency
Aug 11, 2003Mt-Hobble Fire-08/07/2003Fire management
Aug 30, 2000WildfiresMajor disaster
Jul 25, 1997Severe Storms,Ice Jams, Snow Melt, FloodingMajor disaster

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.

2tornadoes
130hail reports, largest 2.5 inches
50damaging thunderstorm winds
10floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Aug 22, 1965F1–0 / 0
May 20, 1973F0–0 / 0

Most damaging storms

DateTypeNearDamage
May 20, 2011FloodMelville$4M
Jul 9, 1994Thunderstorm WindBig Timber$500K
May 20, 1973Tornado–$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 ›
0.4%of homes have federal flood insurance (14 policies)
3.8%of homes in mapped high-risk flood zones are insured
$419,108paid on 10 flood claims since 1978
1997costliest year, with $325,998 paid

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

$330,100median home value (Montana $375,800, US $332,700)
1979median year homes were built (Montana 1981, US 1980)
51%of homes built before 1980, before many modern wind, quake and flood building rules
8.9%of homes are mobile homes, which are the least safe in tornadoes and high winds

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 countiesOverall riskTop hazard
Yellowstone CountyModerateInland flooding
Gallatin CountyModerateEarthquake
Missoula CountyLowInland flooding
Flathead CountyModerateInland flooding
Cascade CountyModerateInland flooding
Lewis and Clark CountyLowCold wave
Ravalli CountyLowWildfire
Silver Bow CountyVery LowCold wave

Neighboring counties

CountyOverall riskDeclarations
Park CountyLow12
Stillwater CountyVery Low14
Wheatland CountyVery Low8
Meagher CountyVery Low8
Golden Valley CountyVery Low8

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.