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Natural hazard risk in Harrison County, Mississippi

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

FEMA overall Risk Index rating: Relatively High (score 95.6 of 100)[5]

Expected annual loss (FEMA)
$154.6 million[1]
Federal disaster declarations since 1965
35[2]
NFIP flood claims paid, 1978 to 2026
$1.29 billion[3]
Tornadoes recorded, 1950 to 2024
86[4]

FEMA's National Risk Index (version 1.20, December 2025) gives Harrison County an overall Risk Index rating of Relatively High, with a score of 95.6 out of 100[5]. FEMA's highest hazard-type scores in this county are for hurricane, lightning and tornado[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 scores compare each county with all other US counties[7]. FEMA rates hurricane risk Very High compared with other US counties, with a score of 98.5[8]. FEMA estimates Expected Annual Loss from all 18 natural hazards at $154.6 million a year[1]. By FEMA's estimates, the largest parts of that loss come from hurricane ($86.6 million a year), inland flooding ($33.2 million a year) and tornado ($11.2 million a year)[9]. Expected Annual Loss is an estimate of average yearly loss, not money anyone paid, and FEMA says the index does not predict next year's losses[7]. FEMA rates Social Vulnerability Relatively High[10]. That describes how susceptible social groups are to harm from natural hazards[10]. FEMA rates Community Resilience Relatively High, which describes a community's ability to prepare for, withstand and recover from hazards[11].

Hazards sorted by FEMA hazard-type Risk Index score, highest first
HazardFEMA risk ratingExpected annual loss
HurricaneVery High$86.6 million[8]
LightningVery High$2.1 million[12]
TornadoRelatively High$11.2 million[13]
Heat WaveRelatively Moderate$4.8 million[14]
WildfireRelatively Moderate$2.5 million[15]
Coastal FloodingRelatively High$5.8 million[16]
Inland FloodingRelatively Moderate$33.2 million[17]
Cold WaveRelatively Moderate$4.8 million[18]
HailRelatively Moderate$1.2 million[19]
Strong WindRelatively High$1.3 million[20]
Ice StormRelatively Moderate$233,000[21]
Winter WeatherRelatively Moderate$130,000[22]
EarthquakeRelatively Low$662,000[23]
DroughtRelatively Low$212,000[24]
LandslideVery Low$317[25]

Rated Not Applicable by FEMA for this county: avalanche, volcanic activity[26].

Social vulnerability and community resilience

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

FEMA measureRatingScore
Social vulnerabilityRelatively High68.8[10]
Community resilienceRelatively High66.1[11]

Flooding and flood insurance

FEMA rates coastal flooding Relatively High, with a score of 91.6[16]. FEMA rates inland flooding Relatively Moderate, with a score of 90.4[17]. OpenFEMA lists 10,601 residential flood insurance contracts in force as of 2026-08-03, out of 73,384 residential structures[27]. Inside FEMA's mapped Special Flood Hazard Area, 62.5% of homes are insured[27]. OpenFEMA's NFIP claims records from 1978 to 2026 show 15,939 claims, and NFIP paid $1.29 billion in total[3]. For the flood zone of a specific address, use FEMA's Flood Map Service Center[28].

Measure Value
Coastal Flooding, FEMA risk rating[16] Relatively High, $5.8 million expected loss a year
Inland Flooding, FEMA risk rating[17] Relatively Moderate, $33.2 million expected loss a year
NFIP residential flood policies in force (2026)[27] 10,601 of 73,384 homes
Homes in FEMA's mapped high-risk flood area (SFHA)[27] 10,451, of which 6,531 insured
NFIP flood claims, 1978 to 2026[3] 15,939 filed, $1.29 billion paid

Is a specific address in a flood zone? Only FEMA's flood maps answer that, property by property[28]. This page describes the whole county.

Search an address on the FEMA Flood Map Service Center

Disaster declarations and tornado records

OpenFEMA lists 35 federal disaster declarations for natural hazards that include Harrison County since 1965[2]. Hurricane accounts for 24 of them[2]. The most recent is DR-4930-MS, Tropical Storm Arthur, declared 2026-08-03[29]. NOAA's tornado database records 86 tornadoes that touched the county from 1950 to 2024[4]. The most recent was on 2024-04-10[4].

Federal disaster declarations for natural hazards that include Harrison County, since 1965
Incident type Declarations
Hurricane[2] 24
Severe Storm[2] 6
Winter Storm[2] 2
Flood[2] 1
Tropical Storm[2] 1
Snowstorm[2] 1
Most recent declarations
Declaration Incident Declared
DR-4930-MS[29] Tropical Storm Arthur 2026-08-03
DR-4899-MS[29] Severe Winter Storm 2026-02-06
EM-3640-MS[29] Severe Winter Storm 2026-01-24
DR-4626-MS[29] Hurricane Ida 2021-10-22
EM-3569-MS[29] Hurricane Ida 2021-08-28

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.

Hurricanes

Before

  • Know your hurricane risk, including rain, wind and tornadoes far inland from landfall.
  • Learn your evacuation zone and routes, and practice them with your household and pets.
  • Keep insurance policies and ID current, with password-protected digital copies.
  • Clear drains and gutters, bring in outdoor furniture and consider hurricane shutters.
  • Keep your phone charged, buy backup chargers and gather supplies, including medication and pet supplies.

During

  • If you are in a mandatory evacuation zone and officials order an evacuation, leave right away.
  • For high winds, take shelter in a designated storm shelter or an interior room.
  • If you are trapped by flooding, go to the highest level, but do not climb into a closed attic.

Source: Ready.gov, hurricanes

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

Extreme heat

Before

  • Learn the signs of heat illness and how to respond.
  • Do not rely on a fan as your main way to stay cool. Fans do not lower body temperature.
  • Find cool public places, such as libraries or malls, or ask your local health department.
  • Keep heat out with window shades, weather stripping and insulation.
  • If you cannot afford cooling costs, contact LIHEAP for help.

During

  • Never leave a person or an animal in a parked car in warm weather.
  • If your home has no air conditioning, go to a cooling center.
  • Wear light, loose clothing, drink plenty of fluids and avoid hard outdoor work in the middle of the day.

Source: Ready.gov, extreme heat

Questions people ask

Is Harrison County at risk of flooding?
FEMA rates coastal flooding Relatively High[16] and inland flooding Relatively Moderate compared with other US counties[17]. NFIP paid $1.29 billion on claims for losses in the county from 1978 to 2026[3].
Is Harrison County at risk of tornadoes?
FEMA rates tornado risk Relatively High compared with other US counties[13]. NOAA's tornado database records 86 tornadoes touching the county from 1950 to 2024[4].
Is Harrison County at risk of hurricanes?
FEMA rates hurricane risk Very High compared with other US counties[8]. OpenFEMA lists 24 hurricane declarations that include the county[2].
How many disasters have been declared in Harrison County?
OpenFEMA lists 35 federal disaster declarations for natural hazards that include the county since 1965[2].
How do I check the flood zone of an address?
Look up the address in FEMA's Flood Map Service Center or ask the local floodplain manager[28].

Facts and sources

  1. FEMA National Risk Index (version 1.20, December 2025): Expected Annual Loss from all 18 natural hazards in Harrison County is $154.6 million a year (Expected Annual Loss rating Relatively Moderate, score 94.2). Of this, buildings account for $126.0 million, injuries and deaths (converted to dollars by FEMA) for... FEMA National Risk Index
  2. OpenFEMA Disaster Declarations Summaries list 35 federal disaster declarations for natural hazards that include Harrison County since 1965 (23 major disaster, 12 emergency or fire management). By incident type: hurricane 24, severe storm 6, winter storm 2, flood 1, tropical storm 1, snowstorm 1. Biological (such as... OpenFEMA Disaster Declarations
  3. HazardFacts tally of OpenFEMA NFIP Redacted Claims (losses from 1978 to 2026): 15,939 National Flood Insurance Program claims were filed for losses in Harrison County, 13,284 of them with a payment, and NFIP paid $1.29 billion in total (building, contents and increased cost of compliance, in dollars of the year... OpenFEMA NFIP claims
  4. NOAA Storm Prediction Center tornado database (1950 to 2024): 86 recorded tornadoes touched Harrison County. The strongest were rated F3 (most recent of them on 1980-05-19). 5 were rated F3/EF3 or stronger. The most recent recorded tornado was on 2024-04-10. 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 Harrison County is Relatively High, with a Risk Index score of 95.6 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 Harrison County are hurricane (98.5, Very High), lightning (97.0, Very High), tornado (95.9, Relatively High). HazardFacts sorted FEMA's published scores; FEMA's scores... FEMA National Risk Index
  7. 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
  8. FEMA National Risk Index (version 1.20, December 2025), hurricane in Harrison County: Risk Index rating Very High (score 98.5 of 100). Expected Annual Loss $86.6 million a year (rating Very High). Annualized frequency 0.24 events per year, from recorded occurrences over a period of record of 172 years for the... FEMA National Risk Index
  9. HazardFacts sorted FEMA's hazard-type Expected Annual Loss values for Harrison County (National Risk Index v1.20): the largest are hurricane ($86.6 million a year), inland flooding ($33.2 million a year), tornado ($11.2 million a year), out of $154.6 million a year from all 18 hazards. FEMA National Risk Index
  10. FEMA National Risk Index (version 1.20, December 2025): Social Vulnerability rating for Harrison County is Relatively High (score 68.8). FEMA describes social vulnerability as how susceptible social groups are to the harm natural hazards cause. FEMA National Risk Index
  11. FEMA National Risk Index (version 1.20, December 2025): Community Resilience rating for Harrison County is Relatively High (score 66.1). FEMA describes community resilience as a community's ability to prepare for, withstand and recover from hazards. FEMA National Risk Index
  12. FEMA National Risk Index (version 1.20, December 2025), lightning in Harrison County: Risk Index rating Very High (score 97.0 of 100). Expected Annual Loss $2.1 million a year (rating Relatively High). Annualized frequency 87 events per year, from recorded occurrences over a period of record of 24 years. FEMA National Risk Index
  13. FEMA National Risk Index (version 1.20, December 2025), tornado in Harrison County: Risk Index rating Relatively High (score 95.9 of 100). Expected Annual Loss $11.2 million a year (rating Relatively High). Annualized frequency 0.75 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  14. FEMA National Risk Index (version 1.20, December 2025), heat wave in Harrison County: Risk Index rating Relatively Moderate (score 94.8 of 100). Expected Annual Loss $4.8 million a year (rating Relatively Moderate). Annualized frequency 13.72 event-days per year, from recorded occurrences over a period of record of... FEMA National Risk Index
  15. FEMA National Risk Index (version 1.20, December 2025), wildfire in Harrison County: Risk Index rating Relatively Moderate (score 94.5 of 100). Expected Annual Loss $2.5 million a year (rating Relatively Moderate). FEMA's modeled annual frequency is 0.0064 events per year. FEMA National Risk Index
  16. FEMA National Risk Index (version 1.20, December 2025), coastal flooding in Harrison County: Risk Index rating Relatively High (score 91.6 of 100). Expected Annual Loss $5.8 million a year (rating Relatively High). FEMA's modeled annual frequency is 6.4798 events per year. FEMA National Risk Index
  17. FEMA National Risk Index (version 1.20, December 2025), inland flooding in Harrison County: Risk Index rating Relatively Moderate (score 90.4 of 100). Expected Annual Loss $33.2 million a year (rating Relatively Moderate). Annualized frequency 1.75 event-days per year, from recorded occurrences over a period of... FEMA National Risk Index
  18. FEMA National Risk Index (version 1.20, December 2025), cold wave in Harrison County: Risk Index rating Relatively Moderate (score 87.7 of 100). Expected Annual Loss $4.8 million a year (rating Relatively High). Annualized frequency 0.95 event-days per year, from recorded occurrences over a period of record of 18... FEMA National Risk Index
  19. FEMA National Risk Index (version 1.20, December 2025), hail in Harrison County: Risk Index rating Relatively Moderate (score 87.4 of 100). Expected Annual Loss $1.2 million a year (rating Relatively Moderate). Annualized frequency 1.92 events per year, from recorded occurrences over a period of record of 37 years. FEMA National Risk Index
  20. FEMA National Risk Index (version 1.20, December 2025), strong wind in Harrison County: Risk Index rating Relatively High (score 85.4 of 100). Expected Annual Loss $1.3 million a year (rating Relatively Moderate). Annualized frequency 1.6 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  21. FEMA National Risk Index (version 1.20, December 2025), ice storm in Harrison County: Risk Index rating Relatively Moderate (score 74.9 of 100). Expected Annual Loss $233,000 a year (rating Relatively Moderate). Annualized frequency 0.58 event-days per year, from recorded occurrences over a period of record of 68... FEMA National Risk Index
  22. FEMA National Risk Index (version 1.20, December 2025), winter weather in Harrison County: Risk Index rating Relatively Moderate (score 74.4 of 100). Expected Annual Loss $130,000 a year (rating Relatively Moderate). Annualized frequency 0.84 events per year, from recorded occurrences over a period of record of 18... FEMA National Risk Index
  23. FEMA National Risk Index (version 1.20, December 2025), earthquake in Harrison County: Risk Index rating Relatively Low (score 70.4 of 100). Expected Annual Loss $662,000 a year (rating Relatively Low). FEMA's modeled annual frequency is 0.001 events per year. FEMA National Risk Index
  24. FEMA National Risk Index (version 1.20, December 2025), drought in Harrison County: Risk Index rating Relatively Low (score 58.8 of 100). Expected Annual Loss $212,000 a year (rating Relatively Low). Annualized frequency 18.7 event-days per year, from recorded occurrences over a period of record of 22 years. FEMA National Risk Index
  25. FEMA National Risk Index (version 1.20, December 2025), landslide in Harrison County: Risk Index rating Very Low (score 33.2 of 100). Expected Annual Loss $317 a year (rating Very Low). FEMA National Risk Index
  26. FEMA National Risk Index (version 1.20, December 2025) rates these hazards Not Applicable for Harrison 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
  27. NFIP Residential Penetration Rates (OpenFEMA, as of 2026-08-03): 10,601 residential flood insurance contracts were in force in Harrison County, out of 73,384 residential structures, a penetration rate of 14.4%. Inside FEMA's mapped Special Flood Hazard Area there were 10,451 residential structures and 6,531... OpenFEMA NFIP penetration rates
  28. 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
  29. 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.