Mahnomen County, Minnesota

What hazards hit Mahnomen County most?

The most frequent records are winter storm records: 124 since 1996. 47% of its winter storm records since 1996 fell in December and January. The rank column places the county among Minnesota's counties by days with a record per 1,000 square miles of land over each hazard's complete period.

Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.

How many tornadoes has Mahnomen County had?

NOAA records 24 tornadoes in Mahnomen County from 1966 to 2023, the strongest rated EF2, with 0 deaths and 0 injuries recorded in the county. That is 36th of 87 Minnesota counties by days with tornadoes per 1,000 square miles since 1950. A tornado that crossed a county line is counted in each county it touched, with the length of its path inside the county.

Counted as whole tornadoes rather than county records, the Storm Prediction Center's database holds 26 tornadoes whose track touched Mahnomen County since 1950 (NOAA's county records number 24: they file a crossing tornado once per county segment, and the two databases differ on some tracks); along their whole tracks they killed 4 people, 0 of them in Mahnomen County.

Map of the strongest tornado tracks in Minnesota.

Source: NOAA NCEI Storm Events Database, tornado records by county (path length in the county, maximum width); ratings as published: F scale before February 1, 2007, EF scale after. Whole-track figures: NOAA Storm Prediction Center tornado database (1950-2025). SPC severe weather database.

When was the last damaging storm in Mahnomen County?

The most recent record with damage, injuries or deaths is the June 24, 2023 tornado ($54,000 in damage in 2025 dollars).

This tornado touched down south of Mahnomen at 4:15 PM. The highest damage it caused was rated as an EF-2. Among the damage it caused as it continued across its 6 mile path was trees snapped and uprooted (both hard and soft wood), metal garage slid off its foundation and collapsed, crop damage, Quonset caved in on one side, roofing blown off homes, broken power line poles, and lifting fuel tankers full of 250 gallons of fuel and throwing them at a barn. Damage dollar amounts are estimated.
National Weather Service event narrative, NOAA Storm Events Database (search the full record, event 1114366)

Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.

The deadliest and costliest records

Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.

Is it getting more frequent?

Records per decade for Mahnomen County's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).

Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).

What time of year?

47% of its winter storm records since 1996 fell in December and January. The two busiest months are in violet.

Source: NOAA NCEI Storm Events Database, records by the month they began.

Federal disaster declarations for Mahnomen County

FEMA's register lists 20 declarations that include Mahnomen County: 17 major disasters, 3 emergencies and 0 fire management assistance declarations. Most were for flood (8) and severe storm (8).

Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.

How many floods has Mahnomen County had?

NOAA's Storm Events Database holds 18 flood or flash flood records for Mahnomen County from 1997 to 2020, on 15 days, with 0 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Mahnomen County ranks 2358th of 2,942 U.S. counties.

The National Flood Insurance Program has paid $150,000 on 10 claims filed in Mahnomen County; the most in one year was 3 in 2001. Claims count insured losses only: uninsured flood damage is not in this file.

Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.

FEMA's modeled risk for Mahnomen County

FEMA's National Risk Index rates Mahnomen County Very Low overall, with an expected annual loss of $2.3 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.

Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.

Counties that share a border with Mahnomen County

1. Polk County 1,469
2. Becker County 951
3. Norman County 640
4. Clearwater County 633
5. Mahnomen County 451

Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.

Next

• Tornadoes in MinnesotaEvery Minnesota tornado since 1950 and the counties with the most per square mile
• Winter storms in MinnesotaThe state's winter storm records, by county, year and month
• The Minnesota recordEvery hazard in the state, its deadliest events and its federal declarations
• FEMA's risk rating for each hazard in Mahnomen CountyThe hazard risk calculator: 18 hazards beside the county's record
• Download Mahnomen County's FEMA declarations (CSV)20 rows: every declaration that named the county, for your own analysis