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Slope County, North Dakota

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

Very Low overall risk
53rd of 53highest risk in North Dakota
$1Mexpected losses a year
8federal declarations
1 in 500homes with flood insurance
Photo: Bold Frontiers, CC BY 2.0

Slope County, North Dakota has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 99% of US counties. It ranks 53rd of 53 counties in North Dakota. The costliest hazards here are cold waves, inland flooding and hail. FEMA estimates about $1.1 million a year in expected losses, or roughly $1,624 per resident. Since 1978 it has been included in 8 federal disaster or emergency declarations for natural events (6 major disasters). The most recent was in October 2013 (severe winter storm). Only 1 home here carries federal flood insurance.

FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.

Top risks in Slope County

$597,348 a yearExpected losses. Damaging events about 11 times a year.
  • Insulate pipes in outside walls, crawl spaces and garages.
  • Know how to shut off the main water valve.
$219,920 a yearExpected losses. Damaging events about once every 30 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.

Hail

Very Low
$96,458 a yearExpected losses. Damaging events about 2 times a year.
  • Ask about the roof age and any impact-rated shingles.
  • Check your home policy for a separate wind and hail deductible.
HazardRatingScoreExpected loss a year
Cold waveLow32.9
$597K
Inland floodingVery Low0.6
$220K
HailVery Low21.6
$96K
Strong windVery Low7.7
$70K
Heat waveVery Low14.2
$40K
TornadoVery Low5.5
$29K
WildfireVery Low38.0
$28K
Winter weatherVery Low21.2
$23K
DroughtVery Low23.9
$12K
Ice stormVery Low14.3
$11K
LightningVery Low1.6
$7K
EarthquakeVery Low0.6
$861
LandslideVery Low8.0
$21

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 very low in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

Federal declarations for natural events that included Slope County. 2020s bar runs to November 2026.

By type

Severe Storm3
Snowstorm2
Flood2
Coastal Storm1

Most recent

Oct 31, 2013Severe Winter StormMajor disaster
Feb 26, 2010Severe Winter StormMajor disaster
Nov 21, 2005Severe Winter Storm and Record And/Or Near Record SnowMajor disaster
Sep 13, 2005Hurricane Katrina EvacuationEmergency
Apr 7, 1997Severe Flooding,Severe Winter Storms, Snowmelt, Spring RainsMajor disaster
Jan 12, 1997Severe Winter Storms and Blizzard ConditionsMajor disaster
Apr 17, 1978Storms, Ice Jams, Snowmelt & FloodingMajor disaster
Feb 16, 1978Blizzard & SnowstormsEmergency

North Dakota also had 25 statewide declarations that did not name single counties.

Storm history since 1960

Tornado risk by county ›

The National Weather Service has logged 164 storm reports in Slope County since 1960 and about $1.9 million in reported damage. The strongest on record here was an F1 tornado on May 19, 1972.

11tornadoes
96hail reports, largest 4.5 inches
53damaging thunderstorm winds
1floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
May 19, 1972F1–0 / 0
Jun 8, 1991F1–0 / 0
Sep 9, 2010EF0Marmarth0 / 0
Jun 8, 1991F0–0 / 0
Jun 20, 1999F0Amidon0 / 0

Most damaging storms

DateTypeNearDamage
Jul 10, 2016HailAmidon$400K
Jul 20, 2017Thunderstorm WindAmidon$400K
Aug 3, 1996Thunderstorm WindNew England$180K
Jul 10, 2016HailAmidon$175K
Jun 6, 2007FloodAmidon$100K
Jul 10, 2016HailMarmarth$100K

Source: NOAA Storm Events Database, county-based reports through Jun 27, 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 Slope County

Check your address flood zone ›
0.2%of homes have federal flood insurance (1 policies)
0%of homes in mapped high-risk flood zones are insured
$0paid on 0 flood claims since 1978
n/acostliest year

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 Slope County

$170,000median home value (North Dakota $249,900, US $332,700)
1961median year homes were built (North Dakota 1982, US 1980)
66%of homes built before 1980, before many modern wind, quake and flood building rules
9.6%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; 456 housing units.

Compare in North Dakota

All 53 ›
Largest countiesOverall riskTop hazard
Cass CountyModerateInland flooding
Burleigh CountyModerateInland flooding
Grand Forks CountyLowInland flooding
Ward CountyLowCold wave
Williams CountyLowCold wave
Stark CountyVery LowCold wave
Morton CountyLowInland flooding
Stutsman CountyLowCold wave

Neighboring counties

CountyOverall riskDeclarations
Stark CountyVery Low14
Fallon County, MTVery Low6
Bowman CountyVery Low11
Hettinger CountyVery Low17
Adams CountyVery Low13
Golden Valley CountyVery Low11
Billings CountyVery Low10

Common questions about Slope County

What is the biggest natural hazard in Slope County?

Cold wave has the highest expected yearly losses in Slope County, about $597,348 a year in FEMA's estimate. Inland flooding is second at $219,920.

How many federal disasters has Slope County had?

Slope County has been included in 8 federal disaster or emergency declarations for natural events since 1978, including 6 major disasters. The most recent was Severe Winter Storm in October 2013.

Is Slope County a high-risk place to live?

Its overall rating is Very Low, 53rd highest of 53 in North Dakota. 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 Slope County?

Standard home insurance does not cover flooding. About 1 in 500 homes in Slope 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 Slope County had?

NOAA records list 11 tornadoes in Slope County since 1950. The strongest was an F1 tornado on May 19, 1972. The weather service has also logged 96 hail reports and 1 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.