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

Arapahoe County Disaster Risk

Arapahoe County, Colorado

FEMA Risk Rating

Relatively Moderate

National Percentile

94th

of 3,144 counties

State Rank

#4

of 64 (1 = highest risk)

Flood Risk

93th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Moderate

Higher than 93% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Moderate

Higher than 85% 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

Risk Overview

About Natural Disaster Risk in Arapahoe County, Colorado

Arapahoe County faces one of Colorado's highest risks

Arapahoe County scores 93.80 on the composite risk scale, among the highest in the state and well above national averages, indicating relatively moderate but substantial multi-hazard exposure. This score reflects acute vulnerabilities to tornadoes, flooding, and other major disaster types.

Among the riskiest counties in Colorado overall

With a composite score of 93.80 versus Colorado's state average of 40.67, Arapahoe faces more than double typical statewide hazard exposure. Only Boulder and Adams counties rival its elevated disaster risk profile.

Arapahoe leads metro Denver in disaster risk

Arapahoe's 93.80 score significantly exceeds Adams (91.19) to the north and outpaces Broomfield (34.70) dramatically, making it the highest-risk county in the immediate Denver region. This elevated exposure reflects geographic and demographic factors that concentrate hazard vulnerability.

Tornadoes and floods dominate the hazard landscape

Tornado risk of 97.23 ranks as the single greatest threat, with flooding close behind at 92.53—both among Colorado's highest recorded scores. Wildfire exposure (84.70) and earthquake risk (85.50) further compound the county's multi-layered vulnerability.

Comprehensive coverage is non-negotiable here

Arapahoe residents must carry both flood insurance (covering the 92.53 risk score) and understand tornado shelter options, as standard homeowner policies exclude both hazards. Earthquake coverage should also be considered given the 85.50 risk level, making multi-peril protection essential.

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

Preparedness Guide

What to Prepare for in Arapahoe County

Top Hazards by Exposure

  1. #1
    TornadoPrepare
    97th percentile
  2. #2
    FloodPrepare
    93th percentile
  3. #3
    EarthquakePrepare
    85th percentile

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

Risk Advisory: Arapahoe County

Risk Verdict

At the 94th percentile nationally, Arapahoe 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 Arapahoe County residents.

Hazard Breakdown

Tornado risk is Arapahoe County's dominant natural hazard, ranked at the 97th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 93th percentile nationally. Additional tracked hazards include earthquake (85th percentile), wildfire (85th percentile).

Preparedness Context

Tornado exposure at the 97th percentile nationally makes Arapahoe 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. Alongside tornado exposure, flood at the 93th percentile nationally means Arapahoe County households face multi-hazard severe-weather seasons that benefit from a single integrated emergency plan covering both threats. In Arapahoe 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 Colorado county average is 53.1 composite points below Arapahoe County's score, a gap that reflects the county's elevated position in the state's hazard distribution.

Is your household prepared for Arapahoe 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 Arapahoe County, CO?
Arapahoe County has a FEMA National Risk Index rating of Relatively Moderate, placing it in the 94th 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 Arapahoe County?
Arapahoe County is evaluated for five major natural hazard types: tornado (97th percentile), flooding (93th percentile), earthquake (85th percentile), wildfire (85th 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 Arapahoe County risk compare to the Colorado average?
Arapahoe County's composite risk percentile is 94th, compared to the Colorado state average of 41th percentile. The state's overall risk rating is Very Low. This means Arapahoe County faces higher natural disaster risk than the typical county in Colorado.
Is Arapahoe County at risk for tornado?
Yes, Arapahoe County's tornado risk is at the 97th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Arapahoe County is at the 93th 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 Arapahoe County higher risk than average?
Arapahoe County's composite risk score of 94th percentile is above the Colorado state average of 41th percentile. This elevated risk is driven by tornado exposure (97th percentile), along with flooding and earthquake and wildfire 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.