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Natural hazard risk in Sussex County, Delaware

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

FEMA overall Risk Index rating: Relatively Moderate (score 94.1 of 100)[5]

Expected annual loss (FEMA)
$119.3 million[1]
Federal disaster declarations since 1965
18[2]
NFIP flood claims paid, 1978 to 2026
$35.7 million[3]
Tornadoes recorded, 1950 to 2024
24[4]

FEMA's National Risk Index rates overall natural hazard risk in Sussex County, Delaware as Relatively Moderate, with a score of 94.1 out of 100[5]. The hazards with the highest FEMA scores within the county are cold wave, coastal flooding and hurricane[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 (version 1.20, December 2025) estimates Expected Annual Loss from all 18 natural hazards at $119.3 million a year[1]. This is a FEMA estimate of average yearly loss, not money anyone paid. FEMA lists the largest hazard-type values as inland flooding ($42.6 million a year), hurricane ($35.3 million a year) and cold wave ($16.8 million a year)[7]. FEMA rates Social Vulnerability as Relatively High, with a score of 70.3[8]. FEMA describes this as how susceptible social groups are to the harm natural hazards cause[8]. FEMA rates Community Resilience as Relatively Moderate, with a score of 59.7[9]. All ratings compare Sussex County with other US counties, and FEMA says the index does not predict next year's losses[10].

Hazards sorted by FEMA hazard-type Risk Index score, highest first
HazardFEMA risk ratingExpected annual loss
Cold WaveRelatively High$16.8 million[11]
Coastal FloodingVery High$14.2 million[12]
HurricaneRelatively High$35.3 million[13]
Winter WeatherVery High$727,000[14]
Inland FloodingRelatively Moderate$42.6 million[15]
Heat WaveRelatively Moderate$2.3 million[16]
DroughtRelatively Moderate$1.1 million[17]
Strong WindRelatively High$1.3 million[18]
WildfireRelatively Low$538,000[19]
LightningRelatively High$665,000[20]
Ice StormRelatively Moderate$385,000[21]
EarthquakeRelatively Low$1.5 million[22]
TornadoRelatively Low$1.6 million[23]
HailRelatively Low$306,000[24]
LandslideVery Low$1,109[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 High70.3[8]
Community resilienceRelatively Moderate59.7[9]

Flooding and flood insurance

FEMA rates coastal flooding risk Very High compared with other US counties, with a score of 97.6[12]. FEMA rates inland flooding Relatively Moderate[15]. OpenFEMA data as of 2026-08-03 show 15,126 residential flood insurance contracts in force, a penetration rate of 12.7%[27]. Inside FEMA's mapped Special Flood Hazard Area, 61.4% of homes are insured[27]. OpenFEMA NFIP claims from 1978 to 2026 total 4,307, and NFIP paid $35.7 million[3]. For a specific address, check FEMA's Flood Map Service Center[28].

Measure Value
Coastal Flooding, FEMA risk rating[12] Very High, $14.2 million expected loss a year
Inland Flooding, FEMA risk rating[15] Relatively Moderate, $42.6 million expected loss a year
NFIP residential flood policies in force (2026)[27] 15,126 of 119,460 homes
Homes in FEMA's mapped high-risk flood area (SFHA)[27] 17,440, of which 10,708 insured
NFIP flood claims, 1978 to 2026[3] 4,307 filed, $35.7 million 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 18 federal disaster declarations for natural hazards that include Sussex County since 1965[2]. Hurricanes account for 6 of them and snowstorms for 5[2]. The most recent listed is DR-4916-DE, a Severe Winter Storm declared 2026-05-29[29]. NOAA's tornado database records 24 tornadoes touching the county from 1950 to 2024[4].

Federal disaster declarations for natural hazards that include Sussex County, since 1965
Incident type Declarations
Hurricane[2] 6
Snowstorm[2] 5
Severe Storm[2] 3
Flood[2] 1
Winter Storm[2] 1
Coastal Storm[2] 1
Drought[2] 1
Most recent declarations
Declaration Incident Declared
DR-4916-DE[29] Severe Winter Storm 2026-05-29
DR-4265-DE[29] Severe Winter Storm And Snowstorm 2016-03-16
DR-4090-DE[29] Hurricane Sandy 2012-11-16
EM-3357-DE[29] Hurricane Sandy 2012-10-29
DR-4037-DE[29] Hurricane Irene 2011-09-30

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

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

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

Questions people ask

Is Sussex County, Delaware at risk of flooding?
FEMA rates coastal flooding risk Very High and inland flooding Relatively Moderate compared with other US counties[12][15]. Inland flooding has the largest Expected Annual Loss value among the hazards, at $42.6 million a year[7].
Does Sussex County get tornadoes?
NOAA's tornado database records 24 tornadoes touching the county from 1950 to 2024[4]. FEMA rates tornado risk Relatively Low compared with other US counties[23].
Is Sussex County at risk of hurricanes?
FEMA rates hurricane risk Relatively High compared with other US counties, with a score of 97.2[13]. OpenFEMA lists 6 hurricane declarations that include the county since 1965[2].
How many disasters have been declared in Sussex County?
OpenFEMA lists 18 federal disaster declarations for natural hazards that include Sussex County since 1965[2].
How do I check my flood zone in Sussex County?
Look up the address in FEMA's Flood Map Service Center or ask the local floodplain manager[28]. County-level ratings do not tell you the flood zone of one address[28].

Facts and sources

  1. FEMA National Risk Index (version 1.20, December 2025): Expected Annual Loss from all 18 natural hazards in Sussex County is $119.3 million a year (Expected Annual Loss rating Relatively Moderate, score 92.2). Of this, buildings account for $83.8 million, injuries and deaths (converted to dollars by FEMA) for $22.9... FEMA National Risk Index
  2. OpenFEMA Disaster Declarations Summaries list 18 federal disaster declarations for natural hazards that include Sussex County since 1965 (13 major disaster, 5 emergency or fire management). By incident type: hurricane 6, snowstorm 5, severe storm 3, flood 1, winter storm 1, coastal storm 1, drought 1. Biological... OpenFEMA Disaster Declarations
  3. HazardFacts tally of OpenFEMA NFIP Redacted Claims (losses from 1978 to 2026): 4,307 National Flood Insurance Program claims were filed for losses in Sussex County, 3,207 of them with a payment, and NFIP paid $35.7 million in total (building, contents and increased cost of compliance, in dollars of the year paid).... OpenFEMA NFIP claims
  4. NOAA Storm Prediction Center tornado database (1950 to 2024): 24 recorded tornadoes touched Sussex County. The strongest were rated EF3 (most recent of them on 2023-04-01). 1 were rated F3/EF3 or stronger. The most recent recorded tornado was on 2023-09-11. 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 Sussex County is Relatively Moderate, with a Risk Index score of 94.1 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 Sussex County are cold wave (98.1, Relatively High), coastal flooding (97.6, Very High), hurricane (97.2, Relatively High). HazardFacts sorted FEMA's published scores;... FEMA National Risk Index
  7. HazardFacts sorted FEMA's hazard-type Expected Annual Loss values for Sussex County (National Risk Index v1.20): the largest are inland flooding ($42.6 million a year), hurricane ($35.3 million a year), cold wave ($16.8 million a year), out of $119.3 million a year from all 18 hazards. FEMA National Risk Index
  8. FEMA National Risk Index (version 1.20, December 2025): Social Vulnerability rating for Sussex County is Relatively High (score 70.3). FEMA describes social vulnerability as how susceptible social groups are to the harm natural hazards cause. FEMA National Risk Index
  9. FEMA National Risk Index (version 1.20, December 2025): Community Resilience rating for Sussex County is Relatively Moderate (score 59.7). FEMA describes community resilience as a community's ability to prepare for, withstand and recover from hazards. FEMA National Risk Index
  10. 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
  11. FEMA National Risk Index (version 1.20, December 2025), cold wave in Sussex County: Risk Index rating Relatively High (score 98.1 of 100). Expected Annual Loss $16.8 million a year (rating Relatively High). Annualized frequency 0.79 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), coastal flooding in Sussex County: Risk Index rating Very High (score 97.6 of 100). Expected Annual Loss $14.2 million a year (rating Very High). FEMA's modeled annual frequency is 3.6547 events per year. FEMA National Risk Index
  13. FEMA National Risk Index (version 1.20, December 2025), hurricane in Sussex County: Risk Index rating Relatively High (score 97.2 of 100). Expected Annual Loss $35.3 million a year (rating Relatively High). Annualized frequency 0.17 events per year, from recorded occurrences over a period of record of 172 years for... FEMA National Risk Index
  14. FEMA National Risk Index (version 1.20, December 2025), winter weather in Sussex County: Risk Index rating Very High (score 96.6 of 100). Expected Annual Loss $727,000 a year (rating Relatively High). Annualized frequency 7.03 events per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  15. FEMA National Risk Index (version 1.20, December 2025), inland flooding in Sussex County: Risk Index rating Relatively Moderate (score 92.8 of 100). Expected Annual Loss $42.6 million a year (rating Relatively Moderate). Annualized frequency 2.54 event-days per year, from recorded occurrences over a period of... FEMA National Risk Index
  16. FEMA National Risk Index (version 1.20, December 2025), heat wave in Sussex County: Risk Index rating Relatively Moderate (score 89.3 of 100). Expected Annual Loss $2.3 million a year (rating Relatively Moderate). Annualized frequency 5.03 event-days per year, from recorded occurrences over a period of record of 18... FEMA National Risk Index
  17. FEMA National Risk Index (version 1.20, December 2025), drought in Sussex County: Risk Index rating Relatively Moderate (score 86.5 of 100). Expected Annual Loss $1.1 million a year (rating Relatively Moderate). Annualized frequency 4.26 event-days per year, from recorded occurrences over a period of record of 22... FEMA National Risk Index
  18. FEMA National Risk Index (version 1.20, December 2025), strong wind in Sussex County: Risk Index rating Relatively High (score 85.5 of 100). Expected Annual Loss $1.3 million a year (rating Relatively Moderate). Annualized frequency 2.36 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  19. FEMA National Risk Index (version 1.20, December 2025), wildfire in Sussex County: Risk Index rating Relatively Low (score 84.7 of 100). Expected Annual Loss $538,000 a year (rating Relatively Low). FEMA's modeled annual frequency is 0.001 events per year. FEMA National Risk Index
  20. FEMA National Risk Index (version 1.20, December 2025), lightning in Sussex County: Risk Index rating Relatively High (score 82.8 of 100). Expected Annual Loss $665,000 a year (rating Relatively Moderate). Annualized frequency 32.75 events per year, from recorded occurrences over a period of record of 24 years. FEMA National Risk Index
  21. FEMA National Risk Index (version 1.20, December 2025), ice storm in Sussex County: Risk Index rating Relatively Moderate (score 82.0 of 100). Expected Annual Loss $385,000 a year (rating Relatively Moderate). Annualized frequency 0.4 event-days per year, from recorded occurrences over a period of record of 68 years. FEMA National Risk Index
  22. FEMA National Risk Index (version 1.20, December 2025), earthquake in Sussex County: Risk Index rating Relatively Low (score 81.4 of 100). Expected Annual Loss $1.5 million a year (rating Relatively Low). FEMA's modeled annual frequency is 0.001 events per year. FEMA National Risk Index
  23. FEMA National Risk Index (version 1.20, December 2025), tornado in Sussex County: Risk Index rating Relatively Low (score 63.3 of 100). Expected Annual Loss $1.6 million a year (rating Relatively Low). Annualized frequency 0.34 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), hail in Sussex County: Risk Index rating Relatively Low (score 60.4 of 100). Expected Annual Loss $306,000 a year (rating Relatively Low). Annualized frequency 0.92 events per year, from recorded occurrences over a period of record of 37 years. FEMA National Risk Index
  25. FEMA National Risk Index (version 1.20, December 2025), landslide in Sussex County: Risk Index rating Very Low (score 50.6 of 100). Expected Annual Loss $1,109 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 Sussex 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): 15,126 residential flood insurance contracts were in force in Sussex County, out of 119,460 residential structures, a penetration rate of 12.7%. Inside FEMA's mapped Special Flood Hazard Area there were 17,440 residential structures and 10,708... 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.