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

Hamilton County Disaster Risk

Hamilton County, Indiana

FEMA Risk Rating

Relatively Moderate

National Percentile

89th

of 3,144 counties

State Rank

#5

of 92 (1 = highest risk)

Flood Risk

91th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Moderate

Higher than 91% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Very Low

Higher than 20% 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 85% of US counties

Hurricane

Tropical cyclone and hurricane risk

Very Low

Higher than 26% of US counties

Risk Overview

About Natural Disaster Risk in Hamilton County, Indiana

Hamilton faces notably high risk

Hamilton County's composite risk score of 88.80 places it in the "Relatively Moderate" category—well above the national average. The county confronts severe tornado exposure (96.76) and exceptional flood risk (91.06), among Indiana's highest levels in both hazards.

Indiana's most hazardous county

Hamilton's 88.80 composite score nearly doubles Indiana's 45.52 state average, making it the highest-risk county in the state by a substantial margin. The county's tornado (96.76) and flood (91.06) exposure far exceed any peer, reflecting its geography and weather patterns.

Significantly riskier than all neighbors

Hamilton County's 88.80 risk towers over adjacent Hancock (44.02) and Hendricks counties (76.81), reflecting uniquely severe tornado and flood hazards. Even Hendricks County, the second-highest-risk neighbor, falls well below Hamilton's threat level.

Tornadoes and flooding define exposure

Tornado risk at 96.76 is the state's highest, making severe convective storms a defining hazard for Hamilton County residents. Flood risk at 91.06 compounds this threat, particularly in bottomland areas vulnerable to river and stormwater inundation.

Invest in multiple protective layers

Homeowners must prioritize safe room construction or basement shelter for tornado protection—this is essential, not optional. Separate flood insurance is critical; elevate HVAC systems and utilities, maintain sump pumps, and review insurance annually given the county's exceptional hazard exposure.

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

Preparedness Guide

What to Prepare for in Hamilton County

Top Hazards by Exposure

  1. #1
    TornadoPrepare
    97th percentile
  2. #2
    FloodPrepare
    91th percentile
  3. #3
    EarthquakePrepare
    85th percentile

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

Risk Advisory: Hamilton County

Risk Verdict

At the 89th percentile nationally, Hamilton County sits in the upper half of U.S. counties for natural disaster exposure. At this risk level, having a documented household preparedness plan — not just awareness — is the meaningful next step for Hamilton County residents.

Hazard Breakdown

Tornado risk is Hamilton County's dominant natural hazard, ranked at the 97th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 91th percentile nationally. Additional tracked hazards include earthquake (85th percentile), hurricane (26th percentile), wildfire (20th percentile).

Preparedness Context

Tornado exposure at the 97th percentile nationally makes Hamilton County a county where a battery-powered weather radio — not just smartphone apps — is a worthwhile household investment, given that mobile networks often fail during severe storms. The secondary flood hazard at the 91th percentile nationally adds seasonal complexity to Hamilton County's preparedness calendar, since flood and tornado risk often peak at different points in the year. In Hamilton County, tornado watches indicate favorable atmospheric conditions while warnings mean rotation has been detected — households benefit from understanding this distinction so they shelter immediately on a warning, not after seeking visual confirmation.

Regional Context

The Indiana county average is 43.3 composite points below Hamilton County's score, a gap that reflects the county's elevated position in the state's hazard distribution.

Is your household prepared for Hamilton 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 Hamilton County, IN?
Hamilton County has a FEMA National Risk Index rating of Relatively Moderate, placing it in the 89th 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 Hamilton County?
Hamilton County is evaluated for five major natural hazard types: tornado (97th percentile), flooding (91th percentile), earthquake (85th percentile), hurricane (26th percentile), wildfire (20th 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 Hamilton County risk compare to the Indiana average?
Hamilton County's composite risk percentile is 89th, compared to the Indiana state average of 46th percentile. The state's overall risk rating is Relatively Low. This means Hamilton County faces higher natural disaster risk than the typical county in Indiana.
Is Hamilton County at risk for tornado?
Yes, Hamilton County's tornado risk is at the 97th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Hamilton County is at the 91th 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 Hamilton County higher risk than average?
Hamilton County's composite risk score of 89th percentile is above the Indiana state average of 46th percentile. This elevated risk is driven by tornado exposure (97th percentile), along with flooding and earthquake 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.