States › Iowa › Jefferson County
Jefferson County, Iowa
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.
Jefferson County, Iowa, has 450 weather events in the NCEI Storm Events record since 1950, most of them winter storms and snow.
That is 103.3 events per 100 square miles, in line with the Iowa figure of 124.6, and 287.6 per 10,000 residents against 218.0 statewide.
12 events fall in the 12 months to 30 Jun 2026. NCEI attributes 0 deaths and 3 injuries to events in the county, with property damage estimated at $30M and crop damage at $19M.
FEMA has designated the county in 12 federal disaster declarations since 1953; the most recent is Covid-19 Pandemic (major disaster, 23 Mar 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" ($7.5M 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.
Compared with Iowa and the United States
| Measure | Jefferson County | Iowa | US |
|---|---|---|---|
| Recorded events since 1950 | 450 | 69,606 | 1,977,440 |
| Events per 100 square miles | 103.3 | 124.6 | 56.0 |
| Events per 10,000 residents | 287.6 | 218.0 | 59.6 |
| Events in the last 12 months | 12 | 1,467 | 62,008 |
| Deaths recorded by NCEI | 0 | 223 | 26,435 |
| Property damage (NCEI estimates) | $30M | $6.5B | $575B |
| NFIP claims per 1,000 residents | 0.0 | 4.6 | 8.1 |
| Average paid NFIP claim | — | $30K | $43K |
| Claims per 100 policies in force, last 10 years | 0.0 | 21.8 | 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: 259 events in the 20 years to 2025 against 151 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 Nov 1975 | Tornado | Tornado | F2 | $250K | — | — | 3 | County |
| 8 May 1988 | Tornado | Tornado | F2 | $25M | — | — | — | County |
| 1 Aug 2003 | Drought | Drought | — | — | $15M | — | — | Forecast zone |
| 13 Sep 1982 | Tornado | Tornado | F2 | $2.5M | — | — | — | County |
| 1 Jul 2005 | Drought | Drought | — | — | $1.8M | — | — | Forecast zone |
| 1 Aug 2005 | Drought | Drought | — | — | $1.4M | — | — | Forecast zone |
| 10 May 2003 | Hail | Hail | 1.75 in | $500K | — | — | — | County |
| 3 May 2005 | Frost/Freeze | Cold | — | — | $396K | — | — | Forecast zone |
| 9 May 1959 | Tornado | Tornado | F3 | $250K | — | — | — | County |
| 13 Aug 2010 | Flood | Flood | — | $250K | — | — | — | County |
| 6 Apr 1997 | High Wind | Wind | 58 mph | $100K | — | — | — | Forecast zone |
| 10 May 2003 | Tornado | Tornado | F0 | $100K | — | — | — | County |
| 10 May 2003 | Tornado | Tornado | F0 | $100K | — | — | — | County |
| 3 Aug 2010 | Thunderstorm Wind | Wind | 70 mph | $100K | — | — | — | County |
| 13 Aug 2010 | Flash Flood | Flood | — | $100K | — | — | — | County |
| 18 Jun 2010 | Lightning | Lightning | — | $100K | — | — | — | 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
| Declared | Number | Type | Incident | Title | Programs |
|---|---|---|---|---|---|
| 23 Mar 2020 | DR-4483 | Major disaster | Biological | Covid-19 Pandemic | Individual assistance, Public assistance |
| 13 Mar 2020 | EM-3480 | Emergency | Biological | Covid-19 | Public assistance |
| 31 Jul 2015 | DR-4234 | Major disaster | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, And Flooding | Public assistance |
| 31 May 2013 | DR-4119 | Major disaster | Flood | Severe Storms, Straight-Line Winds, And Flooding | Public assistance |
| 4 Jan 2008 | DR-1737 | Major disaster | Severe Ice Storm | Severe Winter Storm | Public assistance |
| 14 Mar 2007 | DR-1688 | Major disaster | Severe Storm | Severe Winter Storms | Public assistance |
| 10 Sep 2005 | EM-3239 | Emergency | Hurricane | Hurricane Katrina Evacuation | Public assistance |
| 2 Jul 1998 | DR-1230 | Major disaster | Flood | Severe Storms, Tornadoes And Flooding | Individual assistance |
| 9 Jul 1993 | DR-996 | Major disaster | Flood | Severe Storms & Flooding | Individual assistance, Public assistance |
| 23 May 1973 | DR-386 | Major disaster | Flood | Severe Storms & Flooding | Individual assistance, Public assistance |
| 14 Aug 1969 | DR-269 | Major disaster | Flood | Heavy Rains & Flooding | Individual assistance, Public assistance |
| 22 Apr 1965 | DR-193 | Major disaster | Flood | Flooding | Individual 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
OpenFEMA lists no NFIP claims with this county's code. FEMA counts 4 residential flood policies in force.
National Risk Index
| Hazard (NRI) | Risk rating | Expected annual loss |
|---|---|---|
| Inland flooding | $2,089,651 | |
| Heat wave | $1,243,593 | |
| Tornado | $1,192,624 | |
| Drought | $899,750 | |
| Strong wind | $612,640 | |
| Hail | $591,975 | |
| Lightning | $379,770 | |
| Cold wave | $260,643 | |
| Earthquake | $114,207 | |
| Wildfire | $51,655 | |
| Ice storm | $42,676 | |
| Winter weather | $40,016 | |
| Hurricane | $2,585 | |
| Landslide | $2,019 |
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
| Storm | Year | Closest approach | Max wind while within 100 mi |
|---|---|---|---|
| Unnamed Atlantic storm | 1900 | 41 mi | 46 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.
Questions and answers
How often does it hail in Jefferson County, IA?
NCEI records 93 hail events in Jefferson County since 1950, in 31 different years; that is about 1.2 recorded events a year. 13 reports were golf-ball size (1.75 in) or larger.
Has Jefferson County had a tornado?
Yes. NCEI records 14 tornadoes in Jefferson County since 1950, 5 of them rated (E)F2 or stronger. Tornado deaths recorded: 0.
When was the last federal disaster declaration for Jefferson County?
23 Mar 2020: Covid-19 Pandemic, a major disaster declaration for biological. The county appears in 12 declarations since 1953.
How many flood insurance claims have been filed in Jefferson County, and how much was paid?
OpenFEMA lists no NFIP claims in the county.
Is Jefferson 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 High" for social vulnerability and "Relatively Moderate" for community resilience. These ratings are FEMA's relative comparison across all US counties.
How does Jefferson County compare with the rest of Iowa?
103.3 recorded events per 100 square miles against 124.6 statewide, and 0.0 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.