Olmsted County, Minnesota

What hazards hit Olmsted County most?

The most frequent records are hail reports: 372 since 1959. 49% of its hail reports since 1959 fell in May and June. 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 Olmsted County had?

NOAA records 40 tornadoes in Olmsted County from 1953 to 2026, the strongest rated F4, with 1 death and 48 injuries recorded in the county. That is 12th 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 38 tornadoes whose track touched Olmsted County since 1950 (NOAA's county records number 40: they file a crossing tornado once per county segment, and the two databases differ on some tracks); along their whole tracks they killed 2 people, 1 of them in Olmsted 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 Olmsted County?

The most recent record with damage, injuries or deaths is the April 17, 2026 hail ($150,000 in damage in 2025 dollars).

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

A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.

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 Olmsted 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?

49% of its hail reports since 1959 fell in May and June. The two busiest months are in violet.

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

Federal disaster declarations for Olmsted County

FEMA's register lists 15 declarations that include Olmsted County: 12 major disasters, 3 emergencies and 0 fire management assistance declarations. Most were for flood (4) and severe storm (4).

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 Olmsted County had?

NOAA's Storm Events Database holds 55 flood or flash flood records for Olmsted County from 1997 to 2024, on 41 days, with 0 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Olmsted County ranks 409th of 2,942 U.S. counties.

The National Flood Insurance Program has paid $5.3 million on 719 claims filed in Olmsted County; the most in one year was 462 in 1978. 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 Olmsted County

FEMA's National Risk Index rates Olmsted County Relatively Moderate overall, with an expected annual loss of $93.6 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 Olmsted County

1. Olmsted County 1,083
2. Winona County 762
3. Mower County 732
4. Fillmore County 688
5. Wabasha County 600
6. Goodhue County 583
7. Dodge County 573

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
• Hail in MinnesotaThe state's hail reports, 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 Olmsted CountyThe hazard risk calculator: 18 hazards beside the county's record
• Download Olmsted County's FEMA declarations (CSV)15 rows: every declaration that named the county, for your own analysis