Clay County, Iowa

What hazards hit Clay County most?

The most frequent records are hail reports: 252 since 1957. 49% of its hail reports since 1957 fell in May and June. The rank column places the county among Iowa'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 Clay County had?

NOAA records 42 tornadoes in Clay County from 1954 to 2026, the strongest rated F3, with 0 deaths and 0 injuries recorded in the county. 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 Clay County since 1950 (NOAA's county records number 42: they file a crossing tornado once per county segment, and the two databases differ on some tracks); along their whole tracks they killed 0 people.

Map of the strongest tornado tracks in Iowa.

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 Clay County?

The most recent record with damage, injuries or deaths is the June 21, 2024 flood (1 death and $24.1 million in damage in 2025 dollars).

Rainfall amounts across Clay County from June 20-22 ranged from 3 to 7 inches. Farther north and upstream, up to 10 inches of rain fell across portions of northwest Iowa. This rainfall resulted in extensive overland flooding and record flooding along the Little Sioux and Ocheyedan Rivers. The city of Spencer experienced catastrophic flooding when waters from the Little Sioux and Ocheyedan Rivers overtopped the city's berm system. At peak flooding, approximately 383 people were rescued, leaving hundreds of residents displaced. Eighty homes had collapsed or caved-in foundations and roughly 2,100 structures of the 5,100 throughout the city were damaged by flood waters. Numerous others had sewage backup into their basements. Many other residences outside of Spencer were also impacted by flood water. …
National Weather Service event narrative, NOAA Storm Events Database (search the full record, event 1197156)

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 Clay 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).

High wind and dust storms in the 2020-26: 23 records against 7 in the decade before, 23 of them forecast-zone records. Drought in the 2020-26: 31 records against 10 in the decade before, 31 of them forecast-zone records. Cells marked z rose mostly through zone records. The local National Weather Service office files these once per forecast zone, so a change in how it draws its zones or splits a storm into records moves this count as much as the weather does; read it beside the Clay County days with a record above.

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 1957 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 Clay County

FEMA's register lists 21 declarations that include Clay County: 18 major disasters, 3 emergencies and 0 fire management assistance declarations. Most were for severe storm (9) and flood (7).

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 Clay County had?

NOAA's Storm Events Database holds 188 flood or flash flood records for Clay County from 1997 to 2024, on 113 days, with 1 death. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Clay County ranks 1428th of 2,942 U.S. counties.

The National Flood Insurance Program has paid $5.5 million on 78 claims filed in Clay County; the most in one year was 59 in 2024. 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 Clay County

FEMA's National Risk Index rates Clay County Very Low overall, with an expected annual loss of $17.1 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 Clay County

1. Clay County 1,017
2. Dickinson County 845
3. O'Brien County 826
4. Buena Vista County 712
5. Cherokee County 708
6. Emmet County 624
7. Osceola County 607
8. Pocahontas County 595
9. Palo Alto County 580

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 IowaEvery Iowa tornado since 1950 and the counties with the most per square mile
• Hail in IowaThe state's hail reports, by county, year and month
• The Iowa recordEvery hazard in the state, its deadliest events and its federal declarations
• FEMA's risk rating for each hazard in Clay CountyThe hazard risk calculator: 18 hazards beside the county's record
• Download Clay County's FEMA declarations (CSV)21 rows: every declaration that named the county, for your own analysis