County Hazards

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Brown County, Illinois

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

FIPS 17009 · 6,421 residents (2021) · 306 sq mi · dominant hazard Wind

Hail · 52Tornado · 10Flood · 18Wind · 76Winter · 52
1974-05-30: Hail1985-05-14: Hail1991-10-23: Hail1992-07-09: Hail1992-07-09: Hail1996-06-02: Hail1998-05-12: Hail1998-05-12: Hail1998-10-29: Hail1998-05-12: Hail1998-10-29: Hail1999-02-11: Hail1999-08-12: Hail1999-08-18: Hail2000-04-16: Hail2000-04-16: Hail2000-04-16: Hail2000-04-19: Hail2001-04-05: Hail2001-04-05: Hail2001-04-05: Hail2003-05-09: Hail2004-05-30: Hail2005-09-19: Hail2006-03-11: Hail2008-01-07: Hail2008-06-22: Hail2008-05-30: Hail2009-05-15: Hail2011-04-19: Hail2011-05-22: Hail2011-02-27: Hail2011-02-27: Hail2011-06-10: Hail2013-05-19: Hail2013-06-15: Hail2013-10-30: Hail2014-06-21: Hail2014-05-21: Hail2017-06-17: Hail2017-02-28: Hail2018-12-01: Hail2021-05-03: Hail2021-07-09: Hail2023-03-31: Hail2023-05-07: Hail2023-06-24: Hail2024-06-13: Hail2024-06-25: Hail1955-12-03: Tornado1956-04-27: Tornado1959-03-26: Tornado1959-09-26: Tornado1966-10-14: Tornado1999-08-12: Tornado2003-05-10: Tornado2009-06-02: Tornado2017-02-28: Tornado2023-10-13: Tornado2010-06-08: Flood2011-06-13: Flood2011-05-25: Flood2011-06-25: Flood2013-04-19: Flood2013-06-01: Flood2013-06-15: Flood2013-04-18: Flood2013-05-01: Flood2015-07-11: Flood2020-07-01: Flood1973-05-01: Wind1974-05-30: Wind1980-08-13: Wind1987-05-21: Wind1989-04-26: Wind1990-11-27: Wind1992-06-17: Wind1992-07-02: Wind1992-07-02: Wind1992-07-09: Wind1998-06-29: Wind1998-06-22: Wind1998-11-10: Wind1998-03-27: Wind1998-06-29: Wind1998-03-27: Wind1999-02-11: Wind1999-08-12: Wind1999-08-12: Wind1999-08-12: Wind1999-08-18: Wind1999-06-04: Wind2000-09-11: Wind2000-09-11: Wind2000-07-05: Wind2001-08-22: Wind2002-06-11: Wind2003-08-26: Wind2003-09-26: Wind2003-07-09: Wind2003-07-18: Wind2004-05-30: Wind2005-09-08: Wind2005-09-08: Wind2006-04-02: Wind2006-08-06: Wind2008-07-27: Wind2009-06-19: Wind2009-08-04: Wind2010-08-13: Wind2010-06-01: Wind2011-06-27: Wind2011-04-10: Wind2011-02-27: Wind2011-05-11: Wind2014-07-07: Wind2014-06-03: Wind2015-07-13: Wind2016-07-19: Wind2016-07-19: Wind2016-07-07: Wind2017-06-14: Wind2017-06-17: Wind2018-05-14: Wind2019-07-17: Wind2019-11-26: Wind2019-05-25: Wind2021-07-09: Wind2022-05-25: Wind2022-03-05: Wind2023-03-31: Wind2023-06-29: Wind2024-06-13: Wind2024-06-25: Wind2026-04-17: Wind
Brown County within Illinois. 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 29 Sep 2026; NFIP claims as of 8 Sep 2026.

Between 1950 and 2026, NCEI recorded 261 storm events in Brown County, Illinois, led by damaging wind.

That is 85.4 events per 100 square miles, below the Illinois figure of 120.2, and 406.5 per 10,000 residents against 52.7 statewide.

2 events fall in the 12 months to 30 Jun 2026. NCEI attributes 1 death and 22 injuries to events in the county, with property damage estimated at $3.3M and crop damage at $42K.

FEMA has designated the county in 16 federal disaster declarations since 1953; the most recent is Covid-19 Pandemic (major disaster, 26 Mar 2020).

National Flood Insurance Program policyholders in the county filed 32 claims since 1978, of which 32 were paid, totalling $438K (about $14K per paid claim). FEMA counts 4 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" ($3.2M a year across 18 hazards).

2events, last 12 monthsto 30 Jun 2026
261events since 19501 death, 22 injuries recorded
16disaster declarationslast 26 Mar 2020
32NFIP flood claims$438K paid

Compared with Illinois and the United States

MeasureBrown CountyIllinoisUS
Recorded events since 195026166,7221,977,440
Events per 100 square miles85.4120.256.0
Events per 10,000 residents406.552.759.6
Events in the last 12 months23,23262,008
Deaths recorded by NCEI11,14826,435
Property damage (NCEI estimates)$3.3M$6.9B$575B
NFIP claims per 1,000 residents5.04.28.1
Average paid NFIP claim$14K$14K$43K
Claims per 100 policies in force, last 10 years0.021.116.1

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: 4
Tornado: 1
Hail: 1Wind: 2
Hail: 1Wind: 3
Hail: 15Tornado: 1Flood: 2Wind: 22Winter: 11Heat: 1
Hail: 15Tornado: 2Flood: 5Wind: 22Winter: 21Heat: 16Cold: 3Drought: 3
Hail: 13Tornado: 1Flood: 10Wind: 19Winter: 13Heat: 21Cold: 2Drought: 2
Hail: 7Tornado: 1Flood: 1Wind: 8Winter: 7Heat: 2Cold: 3
41950s11960s31970s41980s521990s872000s812010s292020s
Recorded events in Brown County by decade and hazard group. HailTornadoFloodWindWinterHeatColdDrought NCEI recorded only tornadoes, hail and thunderstorm wind before 1996.

Trend: 137 events in the 20 years to 2025 against 113 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

Wind76
Hail52
Winter52
Heat40
Flood18
Tornado10
Cold8
Drought5
HazardEventsDeathsShare of state's events
■ Wind76—0.3%detail
■ Hail52—0.4%detail
■ Winter52—0.6%detail
■ Heat40—1.2%
■ Flood1810.3%detail
■ Tornado10—0.3%detail
■ Cold8—0.3%
■ Drought5—0.3%

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
15 Jun 2013Flash FloodFlood———1—County
14 Oct 1966TornadoTornadoF2$2.5M——20County
28 Feb 2017TornadoTornadoEF1———1County
13 Oct 2023TornadoTornadoEF1———1County
9 Jul 2021Thunderstorm WindWind81 mph$300K———County
26 Sep 1959TornadoTornadoF1$250K———County
9 Jul 2021HailHail2.75 in$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

DeclaredNumberTypeIncidentTitlePrograms
26 Mar 2020DR-4489Major disasterBiologicalCovid-19 PandemicIndividual assistance, Public assistance
13 Mar 2020EM-3435EmergencyBiologicalCovid-19Public assistance
10 May 2013DR-4116Major disasterFloodSevere Storms, Straight-Line Winds, And FloodingIndividual assistance, Public assistance
17 Mar 2011DR-1960Major disasterSnowstormSevere Winter Storm And SnowstormPublic assistance
29 Dec 2006EM-3269EmergencySnowstormSnowPublic assistance
7 Sep 2005EM-3230EmergencyHurricaneHurricane Katrina EvacuationPublic assistance
15 May 2003DR-1469Major disasterSevere StormSevere Storms, Tornadoes, And FloodingIndividual assistance
21 May 2002DR-1416Major disasterTornadoSevere Storms, Tornadoes And FloodingIndividual assistance, Public assistance
8 Jan 1999EM-3134EmergencySnowstormIl-Winter Storm 1/1/99Public assistance
6 May 1996DR-1112Major disasterSevere StormSevere Storms And FloodingPublic assistance
30 May 1995DR-1053Major disasterSevere StormSevere Storms And FloodingIndividual assistance, Public assistance
9 Jul 1993DR-997Major disasterFloodSevere Storms & FloodingIndividual assistance, Public assistance
13 Dec 1982DR-674Major disasterSevere StormSevere Storms, Tornadoes & FloodingIndividual assistance, Public assistance
30 Apr 1979DR-583Major disasterFloodSevere Storms & FloodingIndividual assistance, Public assistance
10 Jun 1974DR-438Major disasterFloodSevere Storms & FloodingIndividual assistance, Public assistance
26 Apr 1973DR-373Major disasterFloodSevere Storms & FloodingIndividual 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 Brown County, 1978 to 2026 (hover for the amount paid).
Claims since 197832
Paid claims32
Total paid$438K
Average paid claim$14K
Repetitive-loss properties61 severe
Residential policies in force40.2% of 2,149 structures
Year of lossClaimsPaid claimsAmount paidAverage paid
201611$1,623$1,623
201522$24,067$12,034
201333$112,658$37,553
200911$12,668$12,668
200833$99,678$33,226
200244$69,086$17,272
199544$16,703$4,176
199366$56,323$9,387
198511$9,746$9,746
198277$35,940$5,134

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 4.7 of 100
Expected annual loss$3.2MVery Low
Social vulnerabilityRelatively Low
Community resilienceRelatively High
Hazard (NRI)Risk ratingExpected annual loss
Cold waveRelatively Low$922,011
Heat waveRelatively Low$686,342
Inland floodingVery Low$652,947
Strong windRelatively Low$248,978
DroughtRelatively Low$215,610
TornadoVery Low$206,303
HailVery Low$87,305
EarthquakeVery Low$63,945
LightningVery Low$43,009
LandslideRelatively Low$14,514
Ice stormVery Low$11,162
Winter weatherVery Low$10,076
HurricaneVery Low$1,632
WildfireVery Low$84

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

No HURDAT2 track at tropical-storm strength passes within 100 miles of the county's centre point (through the 2025 season).

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 Brown County, IL?

NCEI records 52 hail events in Brown County since 1950, in 25 different years; that is about 0.7 recorded events a year. 10 reports were golf-ball size (1.75 in) or larger.

Has Brown County had a tornado?

Yes. NCEI records 10 tornadoes in Brown County since 1950, 4 of them rated (E)F2 or stronger. Tornado deaths recorded: 0.

When was the last federal disaster declaration for Brown County?

26 Mar 2020: Covid-19 Pandemic, a major disaster declaration for biological. The county appears in 16 declarations since 1953.

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

32 NFIP claims since 1978, 32 of them paid, for $438K in total. FEMA publishes these figures redacted and aggregated; individual properties are not identified.

Is Brown 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 Brown County compare with the rest of Illinois?

85.4 recorded events per 100 square miles against 120.2 statewide, and 5.0 NFIP claims per 1,000 residents against 4.2. 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 29 Sep 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 30 Sep 2026; see the methodology and corrections pages. Hazard hubs: Hail · Tornado · Flood · Wind · Winter.