States › North Dakota › Slope County
Slope County, North Dakota
Recorded hazard history: storm events since 1950, federal disaster declarations since 1953, flood insurance claims since 1978, and FEMA's risk index.
NCEI notes that Storm Data is compiled from a variety of sources including the National Weather Service, other federal, state and local agencies, the media and the public; that property and crop damage figures are estimates; and that some events are recorded by NWS forecast zone rather than by county. FEMA notes that NFIP claim records are redacted and aggregated to protect the privacy of policyholders. NCEI storm records through 30 Jun 2026; OpenFEMA declarations refreshed 1 Oct 2026; NFIP claims as of 8 Sep 2026.
The NCEI record lists 391 events for Slope County, North Dakota, between 1950 and 2026; damaging wind account for the largest share.
That is 32.2 events per 100 square miles, below the North Dakota figure of 48.3, and 5,666.7 per 10,000 residents against 430.4 statewide.
19 events fall in the 12 months to 30 Jun 2026. NCEI attributes 0 deaths and 0 injuries to events in the county, with property damage estimated at $6.3M and crop damage at $630K.
FEMA has designated the county in 10 federal disaster declarations since 1953; the most recent is Covid-19 Pandemic (major disaster, 1 Apr 2020).
OpenFEMA lists no National Flood Insurance Program claims in the county.
FEMA's National Risk Index rates the county's overall risk as "Very Low" and its expected annual loss as "Very Low" ($1.1M a year across 18 hazards).
Compared with North Dakota and the United States
| Measure | Slope County | North Dakota | US |
|---|---|---|---|
| Recorded events since 1950 | 391 | 33,350 | 1,977,440 |
| Events per 100 square miles | 32.2 | 48.3 | 56.0 |
| Events per 10,000 residents | 5,666.7 | 430.4 | 59.6 |
| Events in the last 12 months | 19 | 1,019 | 62,008 |
| Deaths recorded by NCEI | 0 | 100 | 26,435 |
| Property damage (NCEI estimates) | $6.3M | $5.6B | $575B |
| NFIP claims per 1,000 residents | 0.0 | 17.2 | 8.1 |
| Average paid NFIP claim | — | $24K | $43K |
| Claims per 100 policies in force, last 10 years | 0.0 | 4.5 | 16.1 |
County-recorded events plus zone-recorded events whose forecast zone is named for the county. State and US rows include events recorded only by forecast zone. Rates use 2021 Census population and land area.
Events by decade
Trend: 275 events in the 20 years to 2025 against 95 in the 20 years before. Reporting practice changed in 1996 and again with automated reports in the 2000s, so decade totals measure the record as much as the weather.
Events by type
Hazard pages exist for hail, tornado, flood, wind and winter where the county has at least 10 recorded events. "Other" covers heavy rain, debris flow, dust, funnel clouds and similar reports.
Largest recorded events
| Date | Event type | Group | Magnitude | Property damage | Crop damage | Deaths | Injuries | Geography |
|---|---|---|---|---|---|---|---|---|
| 9 Jan 1997 | Blizzard | Winter | — | $1.5M | — | — | — | Forecast zone |
| 4 Apr 1997 | Blizzard | Winter | — | $1.4M | — | — | — | Forecast zone |
| 16 Jul 2011 | Excessive Heat | Heat | — | $700K | — | — | — | Forecast zone |
| 24 Jan 2010 | Blizzard | Winter | — | $588K | — | — | — | Forecast zone |
| 10 Jul 2016 | Hail | Hail | 2.75 in | $150K | $250K | — | — | County |
| 20 Jul 2017 | Thunderstorm Wind | Wind | 92 mph | $400K | — | — | — | County |
| 4 Jan 1997 | Blizzard | Winter | — | $250K | — | — | — | Forecast zone |
| 19 Apr 2006 | Blizzard | Winter | — | $250K | — | — | — | Forecast zone |
| 3 Aug 1996 | Thunderstorm Wind | Wind | 86 mph | $30K | $150K | — | — | County |
| 10 Jul 2016 | Hail | Hail | 1.75 in | $125K | $50K | — | — | County |
| 30 Apr 2011 | Blizzard | Winter | — | $100K | — | — | — | Forecast zone |
Ranked by deaths, then injuries, then NCEI's damage estimate. Deaths and injuries are NCEI counts (direct plus indirect); no personal details are recorded here.
Federal disaster declarations
| Declared | Number | Type | Incident | Title | Programs |
|---|---|---|---|---|---|
| 1 Apr 2020 | DR-4509 | Major disaster | Biological | Covid-19 Pandemic | Individual assistance, Public assistance |
| 13 Mar 2020 | EM-3477 | Emergency | Biological | Covid-19 | Public assistance |
| 31 Oct 2013 | DR-4154 | Major disaster | Severe Storm | Severe Winter Storm | Public assistance |
| 26 Feb 2010 | DR-1879 | Major disaster | Severe Storm | Severe Winter Storm | Public assistance |
| 21 Nov 2005 | DR-1616 | Major disaster | Snowstorm | Severe Winter Storm And Record And/Or Near Record Snow | Public assistance |
| 13 Sep 2005 | EM-3247 | Emergency | Coastal Storm | Hurricane Katrina Evacuation | Public assistance |
| 7 Apr 1997 | DR-1174 | Major disaster | Flood | Severe Flooding,Severe Winter Storms, Snowmelt, Spring Rains | Individual assistance, Public assistance |
| 12 Jan 1997 | DR-1157 | Major disaster | Severe Storm | Severe Winter Storms And Blizzard Conditions | Public assistance |
| 17 Apr 1978 | DR-554 | Major disaster | Flood | Storms, Ice Jams, Snowmelt & Flooding | Individual assistance, Public assistance |
| 16 Feb 1978 | EM-3061 | Emergency | Snowstorm | Blizzard & Snowstorms | Public assistance |
Declarations in which FEMA designated this county, from the OpenFEMA Disaster Declarations Summaries (v2). DR: major disaster; EM: emergency; FM: fire management assistance. Programs show whether individual or public assistance was made available.
Flood insurance claims
OpenFEMA lists no NFIP claims with this county's code. FEMA counts 1 residential flood policies in force.
National Risk Index
| Hazard (NRI) | Risk rating | Expected annual loss |
|---|---|---|
| Cold wave | $597,348 | |
| Inland flooding | $219,920 | |
| Hail | $96,458 | |
| Strong wind | $70,353 | |
| Heat wave | $39,851 | |
| Tornado | $29,202 | |
| Wildfire | $27,913 | |
| Winter weather | $23,171 | |
| Drought | $12,005 | |
| Ice storm | $11,027 | |
| Lightning | $6,765 | |
| Earthquake | $861 | |
| Landslide | $21 |
FEMA National Risk Index, December 2025 release. Ratings are FEMA's relative comparison of counties; expected annual loss is FEMA's modelled estimate of average yearly building, population and agriculture loss. See how to read the NRI.
Hurricane and tropical storm passes
No HURDAT2 track at tropical-storm strength passes within 100 miles of the county's centre point (through the 2025 season).
Questions and answers
How often does it hail in Slope County, ND?
NCEI records 96 hail events in Slope County since 1950, in 34 different years; that is about 1.2 recorded events a year. 33 reports were golf-ball size (1.75 in) or larger.
Has Slope County had a tornado?
Yes. NCEI records 11 tornadoes in Slope County since 1950, 0 of them rated (E)F2 or stronger. Tornado deaths recorded: 0.
When was the last federal disaster declaration for Slope County?
1 Apr 2020: Covid-19 Pandemic, a major disaster declaration for biological. The county appears in 10 declarations since 1953.
How many flood insurance claims have been filed in Slope County, and how much was paid?
OpenFEMA lists no NFIP claims in the county.
Is Slope County in the National Risk Index's high-risk band?
FEMA's National Risk Index (December 2025) rates the county "Very Low" for overall risk, "Very Low" for expected annual loss, "Very Low" for social vulnerability and "Very Low" for community resilience. These ratings are FEMA's relative comparison across all US counties.
How does Slope County compare with the rest of North Dakota?
32.2 recorded events per 100 square miles against 48.3 statewide, and 0.0 NFIP claims per 1,000 residents against 17.2. The comparison table on this page shows each measure beside the state and national figures.
Provenance
Storm events: NOAA NCEI Storm Events Database, yearly details files through 30 Jun 2026 (public domain). Declarations: OpenFEMA DisasterDeclarationsSummaries v2, refreshed 1 Oct 2026. Flood claims: OpenFEMA NfipClaims v3 as of 8 Sep 2026; NfipMultipleLossProperties v1 (2 Aug 2026); NfipResidentialPenetrationRates v1 (3 Aug 2026). Risk index: FEMA National Risk Index, December 2025. Hurricane tracks: NHC HURDAT2 through 2025. Population and area: US Census Bureau, 2021 vintage. Built 1 Oct 2026; see the methodology and corrections pages. Hazard hubs: Hail · Tornado · Flood · Wind · Winter.