County Hazards

States › Iowa › Mahaska County

Mahaska County, Iowa

Recorded hazard history: storm events since 1950, federal disaster declarations since 1953, flood insurance claims since 1978, and FEMA's risk index.

FIPS 19123 · 21,984 residents (2021) · 571 sq mi · dominant hazard Wind

Hail · 91Tornado · 27Flood · 146Wind · 177Winter · 69
1960-06-28: Hail1960-07-29: Hail1961-04-20: Hail1963-04-17: Hail1966-03-21: Hail1969-06-06: Hail1980-06-14: Hail1980-05-29: Hail1984-09-09: Hail1986-04-25: Hail1989-05-24: Hail1989-05-24: Hail1990-10-17: Hail1990-08-28: Hail1990-08-28: Hail1990-03-10: Hail1996-05-09: Hail1996-05-24: Hail1996-05-24: Hail1996-05-24: Hail1996-05-24: Hail1996-05-24: Hail1996-05-24: Hail1996-05-24: Hail1996-05-24: Hail1996-05-24: Hail1996-05-24: Hail1996-05-24: Hail1998-05-20: Hail1998-05-19: Hail1999-04-08: Hail2000-04-19: Hail2000-06-01: Hail2000-09-11: Hail2001-09-20: Hail2002-04-24: Hail2002-05-31: Hail2002-05-08: Hail2002-10-01: Hail2003-05-10: Hail2003-04-30: Hail2003-04-30: Hail2003-05-04: Hail2004-05-31: Hail2006-07-25: Hail2006-07-25: Hail2006-08-13: Hail2007-06-21: Hail2007-04-03: Hail2008-03-27: Hail2008-04-10: Hail2008-06-12: Hail2011-04-03: Hail2011-04-03: Hail2011-04-03: Hail2011-05-22: Hail2011-05-22: Hail2011-06-05: Hail2011-06-05: Hail2011-06-05: Hail2011-06-05: Hail2011-06-05: Hail2011-06-05: Hail2012-04-14: Hail2012-04-14: Hail2012-04-14: Hail2012-08-16: Hail2013-08-06: Hail2013-08-07: Hail2014-06-22: Hail2014-06-22: Hail2014-03-27: Hail2015-06-20: Hail2015-06-20: Hail2017-04-10: Hail2017-04-15: Hail2017-06-15: Hail2023-05-07: Hail2023-05-07: Hail2023-05-07: Hail2023-07-17: Hail2023-07-17: Hail2023-07-28: Hail2024-05-21: Hail1953-06-27: Tornado1956-08-18: Tornado1970-05-12: Tornado1971-05-18: Tornado1978-09-16: Tornado1978-09-16: Tornado1978-06-17: Tornado1979-08-19: Tornado1984-06-07: Tornado1985-05-11: Tornado1988-05-08: Tornado1992-07-02: Tornado2001-06-14: Tornado2003-05-10: Tornado2007-10-02: Tornado2007-10-02: Tornado2007-09-30: Tornado2008-04-10: Tornado2008-05-30: Tornado2011-06-20: Tornado2012-04-14: Tornado2015-11-11: Tornado2015-11-11: Tornado2016-11-28: Tornado2018-07-19: Tornado2018-07-19: Tornado2018-07-19: Tornado2007-04-25: Flood2007-06-01: Flood2007-08-23: Flood2007-08-23: Flood2007-08-23: Flood2007-03-12: Flood2007-04-26: Flood2007-05-06: Flood2007-08-08: Flood2007-08-08: Flood2007-08-08: Flood2007-10-15: Flood2008-03-12: Flood2008-04-18: Flood2008-03-03: Flood2008-05-30: Flood2008-06-03: Flood2008-04-18: Flood2008-04-11: Flood2008-04-25: Flood2008-06-01: Flood2008-07-20: Flood2008-07-29: Flood2009-11-01: Flood2009-03-25: Flood2009-02-09: Flood2009-03-08: Flood2009-03-10: Flood2009-03-08: Flood2009-04-27: Flood2009-03-08: Flood2009-05-29: Flood2009-06-08: Flood2009-06-18: Flood2009-08-27: Flood2009-10-29: Flood2009-10-23: Flood2010-08-04: Flood2010-04-24: Flood2010-05-13: Flood2010-06-23: Flood2010-03-11: Flood2010-06-12: Flood2010-06-26: Flood2010-06-12: Flood2010-06-12: Flood2010-06-12: Flood2010-06-12: Flood2010-08-10: Flood2010-08-09: Flood2010-08-10: Flood2010-08-10: Flood2010-08-10: Flood2010-08-01: Flood2010-08-09: Flood2010-07-08: Flood2010-06-12: Flood2010-07-01: Flood2010-07-01: Flood2011-05-29: Flood2011-06-10: Flood2011-06-14: Flood2011-06-14: Flood2011-06-10: Flood2013-05-26: Flood2013-05-26: Flood2014-09-10: Flood2014-09-10: Flood2015-06-28: Flood2015-07-29: Flood1957-07-03: Wind1958-07-01: Wind1958-07-01: Wind1959-09-26: Wind1960-06-28: Wind1965-05-26: Wind1966-10-14: Wind1969-07-26: Wind1970-08-05: Wind1970-04-05: Wind1971-06-12: Wind1974-04-13: Wind1974-05-29: Wind1974-07-03: Wind1978-06-17: Wind1982-04-16: Wind1984-09-09: Wind1984-06-07: Wind1985-06-23: Wind1986-07-28: Wind1986-07-28: Wind1986-06-21: Wind1987-05-20: Wind1990-07-04: Wind1991-10-24: Wind1991-04-27: Wind1991-04-27: Wind1991-04-27: Wind1992-07-02: Wind1996-05-24: Wind1996-05-09: Wind1997-06-21: Wind1998-06-29: Wind1998-06-29: Wind1998-06-18: Wind1998-06-18: Wind1998-06-18: Wind1998-06-18: Wind1998-06-29: Wind1998-03-30: Wind1999-07-18: Wind2000-06-13: Wind2000-06-01: Wind2000-06-23: Wind2001-06-14: Wind2001-06-14: Wind2002-03-09: Wind2002-04-24: Wind2002-05-08: Wind2002-05-08: Wind2002-07-06: Wind2003-08-20: Wind2003-08-20: Wind2004-05-17: Wind2004-05-17: Wind2004-05-17: Wind2004-07-11: Wind2004-08-25: Wind2005-06-04: Wind2005-06-04: Wind2005-06-29: Wind2005-06-29: Wind2006-07-25: Wind2006-08-13: Wind2006-08-13: Wind2006-08-13: Wind2007-08-23: Wind2007-08-23: Wind2007-08-23: Wind2007-06-07: Wind2007-06-07: Wind2008-05-25: Wind2008-05-25: Wind2008-05-25: Wind2008-05-25: Wind2008-05-25: Wind2008-04-10: Wind2008-04-10: Wind2008-05-30: Wind2008-05-30: Wind2008-06-05: Wind2008-08-05: Wind2008-12-27: Wind2009-06-19: Wind2009-06-19: Wind2009-06-18: Wind2009-06-23: Wind2009-07-15: Wind2009-08-09: Wind2010-06-22: Wind2010-06-22: Wind2010-06-01: Wind2010-04-02: Wind2011-05-29: Wind
Mahaska County within Iowa. Dots: HailTornadoFloodWind event locations in the kept record. Boundaries: US Census Bureau.

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.

Mahaska County, Iowa, has 622 weather events in the NCEI Storm Events record since 1950, most of them damaging wind.

That is 109.0 events per 100 square miles, in line with the Iowa figure of 124.6, and 282.9 per 10,000 residents against 218.0 statewide.

0 events fall in the 12 months to 30 Jun 2026. NCEI attributes 2 deaths and 37 injuries to events in the county, with property damage estimated at $58M and crop damage at $175M.

FEMA has designated the county in 20 federal disaster declarations since 1953; the most recent is Covid-19 Pandemic (major disaster, 23 Mar 2020).

National Flood Insurance Program policyholders in the county filed 11 claims since 1978, of which 8 were paid, totalling $134K (about $17K per paid claim). FEMA counts 12 residential flood policies in force.

FEMA's National Risk Index rates the county's overall risk as "Very Low" and its expected annual loss as "Very Low" ($11M a year across 18 hazards).

1 tropical storm or hurricane track in the HURDAT2 record passed within 100 miles of the county's centre at tropical-storm strength or more, 0 of them within 50 miles at hurricane strength.

0events, last 12 monthsto 30 Jun 2026
622events since 19502 deaths, 37 injuries recorded
20disaster declarationslast 23 Mar 2020
11NFIP flood claims$134K paid

Compared with Iowa and the United States

MeasureMahaska CountyIowaUS
Recorded events since 195062269,6061,977,440
Events per 100 square miles109.0124.656.0
Events per 10,000 residents282.9218.059.6
Events in the last 12 months01,46762,008
Deaths recorded by NCEI222326,435
Property damage (NCEI estimates)$58M$6.5B$575B
NFIP claims per 1,000 residents0.54.68.1
Average paid NFIP claim$17K$30K$43K
Claims per 100 policies in force, last 10 years0.021.816.1

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

Tornado: 2Wind: 4
Hail: 6Wind: 4
Tornado: 6Wind: 7
Hail: 6Tornado: 3Wind: 8
Hail: 19Tornado: 1Flood: 33Wind: 33Winter: 15Cold: 8Drought: 1Lightning: 3Other: 1
Hail: 28Tornado: 7Flood: 54Wind: 59Winter: 22Heat: 1Cold: 1Drought: 4Lightning: 4Other: 1
Hail: 25Tornado: 8Flood: 58Wind: 46Winter: 20Heat: 3Cold: 10Drought: 8Lightning: 1Other: 31
Hail: 7Flood: 1Wind: 16Winter: 12Cold: 5Drought: 19Other: 11
61950s101960s131970s171980s1141990s1812000s2102010s712020s
Recorded events in Mahaska County by decade and hazard group. HailTornadoFloodWindWinterHeatColdDroughtLightningOther NCEI recorded only tornadoes, hail and thunderstorm wind before 1996.

Trend: 373 events in the 20 years to 2025 against 211 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

Wind177
Flood146
Hail91
Winter69
Other44
Drought32
Tornado27
Cold24
Lightning8
Heat4
HazardEventsDeathsShare of state's events
■ Wind17710.8%detail
■ Flood146—2.0%detail
■ Hail91—0.6%detail
■ Winter69—0.6%detail
■ Other44—1.0%
■ Drought32—1.2%
■ Tornado2710.8%detail
■ Cold24—0.9%
■ Lightning8—2.2%
■ Heat4—0.5%

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

DateEvent typeGroupMagnitudeProperty damageCrop damageDeathsInjuriesGeography
7 Jun 1984TornadoTornadoF4$25M—130County
30 May 2003High WindWind40 mph$25K—1—Forecast zone
1 Jul 2012DroughtDrought——$45M——Forecast zone
14 Sep 1996Frost/FreezeCold——$42M——Forecast zone
11 May 1985TornadoTornadoF1$25K——4County
1 Aug 2013DroughtDrought——$21M——Forecast zone
12 Jun 2010FloodFlood——$20M——County
1 Aug 2003DroughtDrought—$13M———Forecast zone
1 Aug 2001DroughtDrought——$11M——Forecast zone
16 Sep 1978TornadoTornado—$250K——1County
27 Jun 1953TornadoTornadoF2$3K——1County
5 Aug 1996LightningLightning————1County
1 Aug 2012DroughtDrought——$6.0M——Forecast zone
1 Sep 2000DroughtDrought——$5.0M——Forecast zone
14 Aug 2000DroughtDrought——$4.7M——Forecast zone
20 Jul 1999DroughtDrought——$4.6M——Forecast zone
26 Oct 1997Heavy SnowWinter—$640K$2.6M——Forecast zone
10 Oct 2009Frost/FreezeCold——$2.5M——Forecast zone
17 Jun 1996FloodFlood—$500K$1.0M——Forecast zone
1 Aug 2010FloodFlood—$1.0M$500K——County

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

DeclaredNumberTypeIncidentTitlePrograms
23 Mar 2020DR-4483Major disasterBiologicalCovid-19 PandemicIndividual assistance, Public assistance
13 Mar 2020EM-3480EmergencyBiologicalCovid-19Public assistance
23 Mar 2019DR-4421Major disasterFloodSevere Storms And FloodingPublic assistance
5 Aug 2014DR-4187Major disasterSevere StormSevere Storms, Tornadoes, Straight-Line Winds, And FloodingPublic assistance
2 Jul 2013DR-4126Major disasterSevere StormSevere Storms, Tornadoes, And FloodingPublic assistance
29 Jul 2010DR-1930Major disasterSevere StormSevere Storms, Flooding, And TornadoesIndividual assistance, Public assistance
27 May 2008DR-1763Major disasterSevere StormSevere Storms, Tornadoes, And FloodingIndividual assistance, Public assistance
4 Jan 2008DR-1737Major disasterSevere Ice StormSevere Winter StormPublic assistance
14 Sep 2007DR-1727Major disasterSevere StormSevere Storms And FloodingPublic assistance
14 Mar 2007DR-1688Major disasterSevere StormSevere Winter StormsPublic assistance
10 Sep 2005EM-3239EmergencyHurricaneHurricane Katrina EvacuationPublic assistance
2 Jul 1998DR-1230Major disasterFloodSevere Storms, Tornadoes And FloodingIndividual assistance, Public assistance
20 Nov 1997DR-1191Major disasterSnowstormSevere SnowstormsPublic assistance
24 Jun 1996DR-1121Major disasterSevere StormSevere Storms And FloodingPublic assistance
9 Jul 1993DR-996Major disasterFloodSevere Storms & FloodingIndividual assistance, Public assistance
26 May 1990DR-868Major disasterFloodSevere Storms & FloodingIndividual assistance, Public assistance
27 Jun 1984DR-715Major disasterSevere StormSevere Storms, Tornadoes, Hail & FloodsIndividual assistance
24 Jun 1974DR-443Major disasterFloodSevere Storms & FloodingIndividual assistance, Public assistance
23 May 1973DR-386Major disasterFloodSevere Storms & FloodingIndividual assistance, Public assistance
22 Apr 1965DR-193Major disasterFloodFloodingIndividual assistance, 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

197820022026
NFIP claims by year of loss in Mahaska County, 1978 to 2026 (hover for the amount paid).
Claims since 197811
Paid claims8
Total paid$134K
Average paid claim$17K
Repetitive-loss properties10 severe
Residential policies in force120.1% of 10,692 structures
Year of lossClaimsPaid claimsAmount paidAverage paid
201311$4,102$4,102
201064$23,653$5,913
200833$106,674$35,558
199310$0—

OpenFEMA NFIP claims (v3, as of 8 Sep 2026), aggregated by year of loss; amounts are building, contents and increased-cost-of-compliance payments as recorded. Repetitive-loss counts from the NFIP Multiple Loss Properties file (2 Aug 2026); policies in force from the NFIP Residential Penetration Rates file (3 Aug 2026).

National Risk Index

Overall riskVery Lowscore 29.7 of 100
Expected annual loss$11MVery Low
Social vulnerabilityRelatively Low
Community resilienceRelatively High
Hazard (NRI)Risk ratingExpected annual loss
Inland floodingRelatively Low$4,888,404
TornadoRelatively Low$1,670,854
DroughtRelatively Moderate$1,346,209
Strong windRelatively Moderate$1,095,085
Cold waveRelatively Low$597,358
Heat waveRelatively Low$537,298
HailRelatively Low$508,846
LightningRelatively Low$152,164
EarthquakeVery Low$81,168
Ice stormRelatively Low$75,684
Winter weatherRelatively Low$65,774
WildfireVery Low$34,347
LandslideVery Low$2,890
HurricaneVery Low$2,654

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

Tracks within 100 miles1
Tracks within 50 miles1
Hurricane strength within 50 miles0
StormYearClosest approachMax wind while within 100 mi
Unnamed Atlantic storm190017 mi46 mph

HURDAT2 best-track positions at tropical-storm strength (34 kt) or more, measured from the county's Census centre point; through the 2025 season. Distance from a track is not the same as the extent of the storm's wind, rain or surge.

ZIP codes with flood claims

ZIP codes whose NFIP claims carry this county's code, with the number of claims. Five or more claims are needed for a ZIP page to be indexed.

Questions and answers

How often does it hail in Mahaska County, IA?

NCEI records 91 hail events in Mahaska County since 1950, in 29 different years; that is about 1.2 recorded events a year. 34 reports were golf-ball size (1.75 in) or larger.

Has Mahaska County had a tornado?

Yes. NCEI records 27 tornadoes in Mahaska County since 1950, 6 of them rated (E)F2 or stronger. Tornado deaths recorded: 1.

When was the last federal disaster declaration for Mahaska County?

23 Mar 2020: Covid-19 Pandemic, a major disaster declaration for biological. The county appears in 20 declarations since 1953.

How many flood insurance claims have been filed in Mahaska County, and how much was paid?

11 NFIP claims since 1978, 8 of them paid, for $134K in total. FEMA publishes these figures redacted and aggregated; individual properties are not identified.

Is Mahaska 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, "Relatively Low" for social vulnerability and "Relatively High" for community resilience. These ratings are FEMA's relative comparison across all US counties.

How does Mahaska County compare with the rest of Iowa?

109.0 recorded events per 100 square miles against 124.6 statewide, and 0.5 NFIP claims per 1,000 residents against 4.6. 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.