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Natural hazard risk in Brown County, Wisconsin

Updated October 30, 2026. Based on FEMA, NOAA and OpenFEMA data. Published by Humblebee.

FEMA overall Risk Index rating: Relatively Moderate (score 90.0 of 100)[5]

Expected annual loss (FEMA)
$103.7 million[1]
Federal disaster declarations since 1973
7[2]
NFIP flood claims paid, 1978 to 2026
$2.3 million[3]
Tornadoes recorded, 1950 to 2024
31[4]

FEMA's National Risk Index rates overall natural hazard risk in Brown County, Wisconsin as Relatively Moderate compared with other US counties[5]. The hazards with the highest FEMA scores within the county are cold wave, hail and lightning[6].

FEMA risk ratings for each hazard

Ratings and expected losses from the FEMA National Risk Index. Each rating compares this county with all US counties for that hazard, from Very Low to Very High. They are planning estimates, not predictions, and they do not describe any single property.

FEMA's National Risk Index estimates $103.7 million a year in Expected Annual Loss from all 18 natural hazards in Brown County[1]. FEMA's estimates put the largest shares in inland flooding, cold wave and tornado, in that order[7]. Expected Annual Loss is FEMA's estimate of average yearly loss, and the index is not meant to predict damage in the next year[8]. FEMA rates Social Vulnerability as Very Low in Brown County, which describes how susceptible social groups are to harm from natural hazards[9]. FEMA rates Community Resilience as Very High, which describes a community's ability to prepare for, withstand and recover from hazards[10].

Hazards sorted by FEMA hazard-type Risk Index score, highest first
HazardFEMA risk ratingExpected annual loss
Cold WaveRelatively High$25.5 million[11]
HailRelatively High$4.1 million[12]
LightningRelatively High$2.3 million[13]
TornadoRelatively High$11.9 million[14]
Inland FloodingRelatively Moderate$57.4 million[15]
Winter WeatherRelatively Moderate$313,000[16]
Heat WaveRelatively Low$1.5 million[17]
LandslideVery Low$2,862[18]
Ice StormRelatively Low$95,000[19]
Coastal FloodingRelatively Low$69,000[20]
EarthquakeVery Low$139,000[21]
WildfireVery Low$22,000[22]
Strong WindRelatively Low$367,000[23]
HurricaneVery Low$12,000[24]

Rated Not Applicable by FEMA for this county: avalanche, volcanic activity[25].

Social vulnerability and community resilience

FEMA uses these two ratings to scale expected losses into the Risk Index.

FEMA measureRatingScore
Social vulnerabilityVery Low17.4[9]
Community resilienceVery High94.9[10]

Flooding and flood insurance

FEMA rates inland flooding risk Relatively Moderate compared with other US counties[15]. OpenFEMA lists 452 residential flood insurance contracts in force in Brown County as of 2026-08-03, a penetration rate of 0.6%[26]. Inside FEMA's mapped Special Flood Hazard Area, 266 flood insurance contracts were in force for 2,666 residential structures, a rate of 10%[26]. OpenFEMA NFIP claims data lists 383 claims for losses from 1978 to 2026, and NFIP paid $2.3 million in total[3]. To learn about the flood zone of a specific address, use FEMA's Flood Map Service Center[27].

Measure Value
Inland Flooding, FEMA risk rating[15] Relatively Moderate, $57.4 million expected loss a year
Coastal Flooding, FEMA risk rating[20] Relatively Low, $69,000 expected loss a year
NFIP residential flood policies in force (2026)[26] 452 of 80,609 homes
Homes in FEMA's mapped high-risk flood area (SFHA)[26] 2,666, of which 266 insured
NFIP flood claims, 1978 to 2026[3] 383 filed, $2.3 million paid

Is a specific address in a flood zone? Only FEMA's flood maps answer that, property by property[27]. This page describes the whole county.

Search an address on the FEMA Flood Map Service Center

Disaster declarations and tornado records

OpenFEMA lists 7 federal disaster declarations for natural hazards that include Brown County since 1973[2]. The most recent listed was DR-4923-WI, Severe Storms, Tornadoes, And Flooding, declared 2026-06-30[28]. NOAA's tornado database records 31 tornadoes that touched Brown County from 1950 to 2024[4]. The most recent recorded tornado was on 2021-08-11[4].

Federal disaster declarations for natural hazards that include Brown County, since 1973
Incident type Declarations
Severe Storm[2] 3
Flood[2] 2
Drought[2] 1
Hurricane[2] 1
Most recent declarations
Declaration Incident Declared
DR-4923-WI[28] Severe Storms, Tornadoes, And Flooding 2026-06-30
EM-3249-WI[28] Hurricane Katrina Evacuation 2005-09-13
DR-1526-WI[28] Severe Storms And Flooding 2004-06-18
DR-994-WI[28] Severe Storms, Tornadoes & Flooding 1993-07-02
DR-874-WI[28] Severe Storms, Tornadoes & Flooding 1990-07-13

How to prepare

Steps from Ready.gov, FEMA's preparedness site, for the hazards with the highest FEMA ratings here. Follow instructions from local officials and the National Weather Service when a warning is issued.

Winter storms and cold

Before

  • Insulate your home and learn how to keep pipes from freezing.
  • Install and test smoke and carbon monoxide detectors with battery backup.
  • Keep several days of supplies in case the power goes out, including medication and pet needs.
  • Put an emergency kit in your car with jumper cables, sand, blankets, water and snacks, and keep the tank full.

During

  • Under a winter storm warning, find shelter right away.
  • Stay off the roads if you can. If you are stuck in your car, stay inside it.
  • Run generators and grills only outdoors, away from windows, and never heat your home with an oven or stove.

Source: Ready.gov, winter storms and cold

Tornadoes

Before

  • Learn the warning signs: a rotating funnel cloud, an approaching cloud of debris or a loud roar like a freight train.
  • Sign up for community warning systems and learn what your local sirens sound like.
  • Pick a safe spot, such as a safe room built to FEMA criteria or an ICC 500 storm shelter, and practice getting there.
  • Include your pets in the household emergency plan.
  • Keep supplies, food, water and medication in case you have to stay home for a long time.

During

  • Go right away to the safe place you picked in advance.
  • Protect your head and neck with your arms and stay away from windows, doors and outside walls.
  • No place in a car is fully safe. If you can get lower than the road, leave the car and lie down there.

Source: Ready.gov, tornadoes

Floods

Before

  • Check your flood risk with FEMA's Flood Map Service Center, and remember that floods do not follow map lines.
  • Sign up for your community's warning system. NOAA Weather Radio also broadcasts alerts.
  • Buy flood insurance through the NFIP well before a disaster. Homeowners policies do not cover flooding, and a new policy typically takes up to 30 days to go into effect.
  • Make a household plan with evacuation routes, shelter locations and what to do in a flash flood.
  • Keep important documents in a waterproof container and make password-protected digital copies.

During

  • If you are told to evacuate, leave right away and never drive around barricades.
  • Do not walk, swim or drive through floodwater. Six inches of moving water can knock you down.
  • If you are trapped in a building, go to the highest level, but do not climb into a closed attic.

Source: Ready.gov, floods

Questions people ask

Is Brown County, Wisconsin at risk of flooding?
FEMA rates inland flooding risk Relatively Moderate compared with other US counties[15]. FEMA rates coastal flooding Relatively Low[20].
Does Brown County have tornado risk?
FEMA rates tornado risk Relatively High compared with other US counties[14]. NOAA's tornado database records 31 tornadoes touching the county from 1950 to 2024[4].
Is Brown County at risk of earthquakes or hurricanes?
FEMA rates earthquake risk Very Low[21] and hurricane risk Very Low compared with other US counties[24].
How many disasters have been declared in Brown County?
OpenFEMA lists 7 federal disaster declarations for natural hazards that include Brown County since 1973[2].
How do I check the flood zone of an address in Brown County?
Look up the address in FEMA's Flood Map Service Center or ask the local floodplain manager[27].

Facts and sources

  1. FEMA National Risk Index (version 1.20, December 2025): Expected Annual Loss from all 18 natural hazards in Brown County is $103.7 million a year (Expected Annual Loss rating Relatively Moderate, score 90.9). Of this, buildings account for $67.4 million, injuries and deaths (converted to dollars by FEMA) for $35.2... FEMA National Risk Index
  2. OpenFEMA Disaster Declarations Summaries list 7 federal disaster declarations for natural hazards that include Brown County since 1973 (5 major disaster, 2 emergency or fire management). By incident type: severe storm 3, flood 2, drought 1, hurricane 1. Biological (such as COVID-19) and other non-natural... OpenFEMA Disaster Declarations
  3. HazardFacts tally of OpenFEMA NFIP Redacted Claims (losses from 1978 to 2026): 383 National Flood Insurance Program claims were filed for losses in Brown County, 238 of them with a payment, and NFIP paid $2.3 million in total (building, contents and increased cost of compliance, in dollars of the year paid). Years... OpenFEMA NFIP claims
  4. NOAA Storm Prediction Center tornado database (1950 to 2024): 31 recorded tornadoes touched Brown County. The strongest were rated F3 (most recent of them on 1969-06-26). 1 were rated F3/EF3 or stronger. The most recent recorded tornado was on 2021-08-11. Ratings used the Fujita scale until early 2007 and the... NOAA Storm Prediction Center
  5. FEMA National Risk Index (version 1.20, December 2025): the overall natural hazard Risk Index rating for Brown County is Relatively Moderate, with a Risk Index score of 90.0 out of 100. The score is the county's percentile rank among all US counties. FEMA National Risk Index
  6. Among the 18 hazards in the FEMA National Risk Index (version 1.20, December 2025), the hazards with the highest hazard-type Risk Index scores for Brown County are cold wave (98.0, Relatively High), hail (95.6, Relatively High), lightning (95.0, Relatively High). HazardFacts sorted FEMA's published scores; FEMA's... FEMA National Risk Index
  7. HazardFacts sorted FEMA's hazard-type Expected Annual Loss values for Brown County (National Risk Index v1.20): the largest are inland flooding ($57.4 million a year), cold wave ($25.5 million a year), tornado ($11.9 million a year), out of $103.7 million a year from all 18 hazards. FEMA National Risk Index
  8. FEMA's National Risk Index FAQ (December 2025): Expected Annual Loss is FEMA's estimate of the average economic loss in dollars from natural hazards each year. The index is not meant to predict how much damage a community will have in the next year, and a hazard can still cause damage where a rating is low. Scores... FEMA National Risk Index documentation
  9. FEMA National Risk Index (version 1.20, December 2025): Social Vulnerability rating for Brown County is Very Low (score 17.4). FEMA describes social vulnerability as how susceptible social groups are to the harm natural hazards cause. FEMA National Risk Index
  10. FEMA National Risk Index (version 1.20, December 2025): Community Resilience rating for Brown County is Very High (score 94.9). FEMA describes community resilience as a community's ability to prepare for, withstand and recover from hazards. FEMA National Risk Index
  11. FEMA National Risk Index (version 1.20, December 2025), cold wave in Brown County: Risk Index rating Relatively High (score 98.0 of 100). Expected Annual Loss $25.5 million a year (rating Very High). Annualized frequency 5.58 event-days per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  12. FEMA National Risk Index (version 1.20, December 2025), hail in Brown County: Risk Index rating Relatively High (score 95.6 of 100). Expected Annual Loss $4.1 million a year (rating Relatively High). Annualized frequency 1.84 events per year, from recorded occurrences over a period of record of 37 years. FEMA National Risk Index
  13. FEMA National Risk Index (version 1.20, December 2025), lightning in Brown County: Risk Index rating Relatively High (score 95.0 of 100). Expected Annual Loss $2.3 million a year (rating Relatively High). Annualized frequency 30.87 events per year, from recorded occurrences over a period of record of 24 years. FEMA National Risk Index
  14. FEMA National Risk Index (version 1.20, December 2025), tornado in Brown County: Risk Index rating Relatively High (score 93.4 of 100). Expected Annual Loss $11.9 million a year (rating Relatively High). Annualized frequency 0.22 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  15. FEMA National Risk Index (version 1.20, December 2025), inland flooding in Brown County: Risk Index rating Relatively Moderate (score 91.8 of 100). Expected Annual Loss $57.4 million a year (rating Relatively Moderate). Annualized frequency 1.11 event-days per year, from recorded occurrences over a period of record... FEMA National Risk Index
  16. FEMA National Risk Index (version 1.20, December 2025), winter weather in Brown County: Risk Index rating Relatively Moderate (score 83.8 of 100). Expected Annual Loss $313,000 a year (rating Relatively High). Annualized frequency 15.84 events per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  17. FEMA National Risk Index (version 1.20, December 2025), heat wave in Brown County: Risk Index rating Relatively Low (score 75.9 of 100). Expected Annual Loss $1.5 million a year (rating Relatively Low). Annualized frequency 1.53 event-days per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  18. FEMA National Risk Index (version 1.20, December 2025), landslide in Brown County: Risk Index rating Very Low (score 57.7 of 100). Expected Annual Loss $2,862 a year (rating Very Low). FEMA National Risk Index
  19. FEMA National Risk Index (version 1.20, December 2025), ice storm in Brown County: Risk Index rating Relatively Low (score 47.7 of 100). Expected Annual Loss $95,000 a year (rating Relatively Low). Annualized frequency 0.21 event-days per year, from recorded occurrences over a period of record of 68 years. FEMA National Risk Index
  20. FEMA National Risk Index (version 1.20, December 2025), coastal flooding in Brown County: Risk Index rating Relatively Low (score 46.4 of 100). Expected Annual Loss $69,000 a year (rating Relatively Low). FEMA's modeled annual frequency is 0.0134 events per year. FEMA National Risk Index
  21. FEMA National Risk Index (version 1.20, December 2025), earthquake in Brown County: Risk Index rating Very Low (score 35.3 of 100). Expected Annual Loss $139,000 a year (rating Very Low). FEMA's modeled annual frequency is 0.0004 events per year. FEMA National Risk Index
  22. FEMA National Risk Index (version 1.20, December 2025), wildfire in Brown County: Risk Index rating Very Low (score 33.8 of 100). Expected Annual Loss $22,000 a year (rating Very Low). FEMA's modeled annual frequency is 0 events per year. FEMA National Risk Index
  23. FEMA National Risk Index (version 1.20, December 2025), strong wind in Brown County: Risk Index rating Relatively Low (score 30.9 of 100). Expected Annual Loss $367,000 a year (rating Relatively Low). Annualized frequency 1.97 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  24. FEMA National Risk Index (version 1.20, December 2025), hurricane in Brown County: Risk Index rating Very Low (score 26.1 of 100). Expected Annual Loss $12,000 a year (rating Very Low). Annualized frequency 0.01 events per year, from recorded occurrences over a period of record of 172 years for the Atlantic Basin... FEMA National Risk Index
  25. FEMA National Risk Index (version 1.20, December 2025) rates these hazards Not Applicable for Brown County: avalanche, volcanic activity. FEMA uses Not Applicable when its source data has no historical record of the hazard in the community and the hazard is not considered geographically possible there. FEMA National Risk Index documentation
  26. NFIP Residential Penetration Rates (OpenFEMA, as of 2026-08-03): 452 residential flood insurance contracts were in force in Brown County, out of 80,609 residential structures, a penetration rate of 0.6%. Inside FEMA's mapped Special Flood Hazard Area there were 2,666 residential structures and 266 contracts, a rate... OpenFEMA NFIP penetration rates
  27. FEMA's Flood Map Service Center is the official public source for flood maps (Flood Insurance Rate Maps) produced under the National Flood Insurance Program. Flood zones apply to specific properties: look up an address there or ask the local floodplain manager. County-level ratings do not tell you the flood zone of... FEMA Flood Map Service Center
  28. Most recent federal disaster declarations for natural hazards (table on this page). OpenFEMA Disaster Declarations

FEMA's National Risk Index compares each county with all other US counties. Ratings are relative (Very Low to Very High), not a measure of safety. Never call a place safe, unsafe, good or bad to live in. Risk Index and Expected Annual Loss values are FEMA estimates for planning. They do not predict next year's losses and do not apply to a single property. Flood zones are set by FEMA flood maps for specific properties. County ratings and flood insurance counts do not tell anyone whether an address is in a flood zone. Disaster declaration, NFIP and tornado counts are records of the past for this county only. Do not compare with other counties unless a fact does.

Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties, v1.20 (December 2025). Retrieved from fema.maps.arcgis.com on October 30, 2026. This product uses the Federal Emergency Management Agency's National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s). This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.