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

Jefferson County Disaster Risk

Jefferson County, Colorado

FEMA Risk Rating

Relatively High

National Percentile

95th

of 3,144 counties

State Rank

#2

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

Very High

Higher than 100% 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 84% of US counties

Risk Overview

About Natural Disaster Risk in Jefferson County, Colorado

Jefferson County faces elevated national risk

With a composite risk score of 94.94, Jefferson County far exceeds the national average and earns a "Relatively High" rating. This suburban Denver county faces significant exposure across nearly all major hazard types.

Colorado's riskiest county overall

Jefferson's 94.94 score dwarfs Colorado's state average of 40.67, making it the state's highest-risk county by a substantial margin. Urban density combined with wildfire proximity creates compounded hazards.

Far riskier than all neighboring counties

Jefferson's 94.94 score vastly exceeds nearby Gilpin County (6.36), Gunnison County (44.97), and all other neighbors. Its position at the western edge of the Denver metro makes it uniquely exposed.

All hazards pose significant threats

Jefferson faces exceptionally high wildfire risk (99.52), tornado risk (96.50), flood risk (93.45), and earthquake risk (84.03)—all well above state and national norms. This multi-hazard exposure requires comprehensive preparation.

Comprehensive coverage is non-negotiable

Jefferson County residents must secure wildfire, flood, and earthquake coverage through riders or separate policies—standard homeowner insurance won't suffice. Given the county's exceptional risk profile, full coverage across all major hazards is essential.

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

Preparedness Guide

What to Prepare for in Jefferson County

Top Hazards by Exposure

  1. #1
    WildfirePrepare
    100th percentile
  2. #2
    TornadoPrepare
    97th percentile
  3. #3
    FloodPrepare
    93th percentile

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

Local Resources

Risk Advisory: Jefferson County

Risk Verdict

Jefferson County ranks in the top tier for natural disaster risk nationally, with a composite score at the 95th percentile. Comprehensive household preparedness — including reviewing insurance, maintaining emergency supplies, and knowing evacuation routes — is strongly recommended.

Hazard Breakdown

Wildfire risk is Jefferson County's dominant natural hazard, ranked at the 100th percentile nationally under FEMA's National Risk Index. Tornado ranks second at the 97th percentile nationally. Additional tracked hazards include flood (93th percentile), earthquake (84th percentile).

Preparedness Context

Jefferson County's dominant hazard is wildfire, ranked at the 100th percentile nationally. Maintaining at least 30 feet of lean, clean vegetation around structures in Jefferson County and keeping gutters clear of debris significantly reduces ignition risk from wind-driven embers. The county's tornado exposure at the 97th percentile nationally complements the wildfire risk — saturating rain after burn scarring often triggers secondary flood and debris flow events. Jefferson County's households benefit from reviewing homeowners insurance before fire season, specifically whether the policy covers replacement cost rather than actual cash value, and whether it includes additional living expenses if displacement is required.

Regional Context

Compared to other Colorado counties, Jefferson County runs 54.3 composite risk points higher than the state mean — reflecting above-average hazard concentration in this area.

Is your household prepared for Jefferson 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 Jefferson County, CO?
Jefferson 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 Jefferson County?
Jefferson County is evaluated for five major natural hazard types: wildfire (100th percentile), tornado (97th percentile), flooding (93th percentile), earthquake (84th percentile). The highest-risk hazard is wildfire at the 100th 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 Jefferson County risk compare to the Colorado average?
Jefferson County's composite risk percentile is 95th, compared to the Colorado state average of 41th percentile. The state's overall risk rating is Very Low. This means Jefferson County faces higher natural disaster risk than the typical county in Colorado.
Is Jefferson County at risk for wildfire?
Yes, Jefferson County's wildfire risk is at the 100th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Jefferson 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 Jefferson County higher risk than average?
Jefferson County's composite risk score of 95th percentile is above the Colorado state average of 41th percentile. This elevated risk is driven by wildfire exposure (100th percentile), along with tornado and flooding and earthquake risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.

Counties with Similar Risk

Denver County

Colorado

+0.3

Relatively High

95th percentile

El Paso County

Colorado

-0.9

Relatively Moderate

94th percentile

Arapahoe County

Colorado

-1.1

Relatively Moderate

94th percentile

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.

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