riskbycounty
FEMA NRI 1.19.0Updated Nov 2023 · Coverage 2014–2023Methodology

Gwinnett County Disaster Risk

Gwinnett County, Georgia

FEMA Risk Rating

Relatively High

National Percentile

95th

of 3,144 counties

State Rank

#3

of 159 (1 = highest risk)

Flood Risk

97th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Relatively High

Higher than 97% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Relatively Low

Higher than 46% of US counties

Tornado

Tornado and severe thunderstorm risk

Relatively High

Higher than 97% of US counties

Earthquake

Seismic activity and ground shaking risk

Moderate

Higher than 93% of US counties

Hurricane

Tropical cyclone and hurricane risk

Relatively Low

Higher than 71% of US counties

Risk Overview

About Natural Disaster Risk in Gwinnett County, Georgia

Gwinnett: Georgia's Highest-Risk County

Gwinnett County scores 95.42 on the composite risk index, far exceeding the national average and earning a relatively high-risk rating. This exceptional score is driven by extreme flood risk (97.39) and tornado risk (97.49), making it one of Georgia's most hazard-prone counties.

Tops Georgia's Risk Rankings

Gwinnett's score of 95.42 is the highest in Georgia, more than double the state average of 39.49. The county's urban density and geography combine to create outsized vulnerability to flooding and severe storms.

Dramatically Riskier Than Surrounding Area

Gwinnett's risk score of 95.42 towers above neighboring counties—Hall (84.26), Greene (37.25), and Habersham (38.90) all face significantly lower hazard exposure. Its exceptional urbanization creates concentrated risk that sets it apart regionally.

Flood and Tornado Risks Are Extreme

Gwinnett faces flood risk at 97.39 and tornado risk at 97.49, placing it in Georgia's top tier for both hazards. Earthquake risk is also elevated at 93.26, creating a multi-threat environment requiring comprehensive preparation.

Flood Insurance Is Non-Negotiable

With flood risk at 97.39, Gwinnett residents should treat flood insurance as essential regardless of mortgage requirements. Homeowners should also verify comprehensive coverage for wind and hail damage, and consider a safe room or shelter plan for tornado events.

Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor

Preparedness Guide

What to Prepare for in Gwinnett County

Top Hazards by Exposure

  1. #1
    TornadoPrepare
    97th percentile
  2. #2
    FloodPrepare
    97th percentile
  3. #3
    EarthquakePrepare
    93th percentile

Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)

Risk Advisory: Gwinnett County

Risk Verdict

FEMA's National Risk Index places Gwinnett County at the 95th percentile nationally — in the high-risk bracket for U.S. counties. Residents should prioritize a formal household emergency plan, including evacuation routes, insurance review, and a well-stocked emergency kit.

Hazard Breakdown

Tornado risk is Gwinnett County's dominant natural hazard, ranked at the 97th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 97th percentile nationally. Additional tracked hazards include earthquake (93th percentile), hurricane (71th percentile), wildfire (46th percentile).

Preparedness Context

With tornado ranked at the 97th percentile nationally, Gwinnett County sits in a high-exposure zone where the difference between outcomes often comes down to proximity to a reinforced interior shelter and seconds of warning time. Alongside tornado exposure, flood at the 97th percentile nationally means Gwinnett County households face multi-hazard severe-weather seasons that benefit from a single integrated emergency plan covering both threats. For Gwinnett County households, safe rooms certified to FEMA 320/361 standards offer the highest protection during a direct tornado hit; households without a safe room should locate the innermost lowest-floor room in their building and practice the route to it before storm season.

Regional Context

Gwinnett County is 55.9 composite risk points above the Georgia average, indicating that residents face greater natural hazard exposure than most of their in-state neighbors.

Is your household prepared for Gwinnett County's hazards?

Review FEMA's county-specific preparedness checklists and emergency planning guides.

FEMA Ready Guide →

Frequently Asked Questions

What is the natural disaster risk in Gwinnett County, GA?
Gwinnett County has a FEMA National Risk Index rating of Relatively High, placing it in the 95th percentile nationally out of 3,144 counties. This composite score reflects the county's overall exposure to natural hazards including floods, wildfires, tornadoes, earthquakes, and hurricanes, weighted by expected annual loss and social vulnerability.
What types of natural hazards affect Gwinnett County?
Gwinnett County is evaluated for five major natural hazard types: tornado (97th percentile), flooding (97th percentile), earthquake (93th percentile), hurricane (71th percentile), wildfire (46th percentile). The highest-risk hazard is tornado at the 97th percentile nationally. These scores are derived from FEMA's National Risk Index, which analyzes expected annual loss, social vulnerability, and community resilience for each hazard type.
How does Gwinnett County risk compare to the Georgia average?
Gwinnett County's composite risk percentile is 95th, compared to the Georgia state average of 40th percentile. The state's overall risk rating is Very Low. This means Gwinnett County faces higher natural disaster risk than the typical county in Georgia.
Is Gwinnett County at risk for tornado?
Yes, Gwinnett County's tornado risk is at the 97th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Gwinnett County is at the 97th percentile.
How is natural disaster risk measured?
FEMA's National Risk Index (NRI) calculates risk scores for 18 natural hazard types across all U.S. counties and census tracts. The composite score combines Expected Annual Loss (estimated dollar losses from each hazard), Social Vulnerability (demographic factors affecting disaster impact), and Community Resilience (ability to recover). Percentile scores rank each county against all 3,144 U.S. counties, and risk ratings range from Very Low to Very High.
Why is Gwinnett County higher risk than average?
Gwinnett County's composite risk score of 95th percentile is above the Georgia state average of 40th percentile. This elevated risk is driven by tornado exposure (97th percentile), along with flooding and earthquake and hurricane risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.
By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

Data Source

Risk data sourced from the FEMA National Risk Index (NRI). Risk scores are relative rankings (0–100) across all US counties — not absolute risk measures. Higher scores indicate higher relative risk compared to other counties.

Disclaimer: This data is informational only. It is not financial, insurance, or legal advice. Always consult a qualified professional before making insurance or real estate decisions.