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

Imperial County Disaster Risk

Imperial County, California

FEMA Risk Rating

Relatively High

National Percentile

96th

of 3,144 counties

State Rank

#25

of 58 (1 = highest risk)

Flood Risk

94th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Moderate

Higher than 94% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Relatively Low

Higher than 76% of US counties

Tornado

Tornado and severe thunderstorm risk

Very Low

Higher than 11% of US counties

Earthquake

Seismic activity and ground shaking risk

Relatively High

Higher than 99% of US counties

Hurricane

Tropical cyclone and hurricane risk

Very Low

Higher than 22% of US counties

Risk Overview

About Natural Disaster Risk in Imperial County, California

Imperial County carries relatively high risk

Imperial County's composite risk score of 96.47 places it in the 'Relatively High' category, substantially above the national average. The county's desert location and proximity to major fault lines create sustained exposure to earthquakes and floods. This elevated rating reflects the serious, multifaceted disaster risks that characterize Imperial County.

Imperial ranks among state's top-risk counties

Imperial's 96.47 score significantly exceeds California's 88.72 average, positioning it in the upper tier of the state's 58 counties. The county's earthquake risk of 99.20 alone places it among the state's highest-risk areas. This statewide comparison underscores Imperial's particularly challenging natural hazard exposure.

Imperial's risks rival inland valley peers

Imperial's 96.47 score aligns closely with Humboldt (96.76) and Imperial (96.47), while exceeding Inyo (79.33) and Glenn (74.43). The county's earthquake risk of 99.20 is among the state's highest, reflecting its proximity to major seismic systems. Among southern California counties, Imperial stands out for consistently elevated composite risk.

Earthquake dominates Imperial's hazard profile

Imperial's earthquake risk scores an extreme 99.20, the county's most pressing natural hazard, while flood risk reaches 94.12. Notably, Imperial is one of the few California counties with measurable hurricane risk (22.32), though this remains secondary to earthquake and flood threats. These three hazards demand serious preparedness attention from all Imperial residents.

Earthquake coverage is non-negotiable

Imperial residents must obtain earthquake insurance immediately, given the county's extreme 99.20 score—among California's highest. Flood insurance is also essential, particularly for those in flood-prone areas near the Salton Sea or irrigation channels. Together with standard homeowners coverage, these policies create protection against Imperial's primary disaster threats.

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

Preparedness Guide

What to Prepare for in Imperial County

Top Hazards by Exposure

  1. #1
    EarthquakePrepare
    99th percentile
  2. #2
    FloodPrepare
    94th percentile
  3. #3
    WildfirePrepare
    76th percentile

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

Risk Advisory: Imperial County

Risk Verdict

With a national rank of 96th percentile, Imperial County faces above-average natural disaster pressure across several hazard categories. High composite risk signals that multiple hazard types are elevated simultaneously; planning for more than one scenario is important in Imperial County.

Hazard Breakdown

Earthquake risk is Imperial County's dominant natural hazard, ranked at the 99th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 94th percentile nationally. Additional tracked hazards include wildfire (76th percentile), hurricane (22th percentile), tornado (11th percentile).

Preparedness Context

Imperial County's primary hazard, earthquake, ranks at the 99th percentile nationally. Unreinforced masonry structures carry the highest injury risk during seismic events; residents in older buildings should check with their municipality about available seismic retrofit programs. The county's flood risk at the 94th percentile nationally is a seasonal consideration alongside the year-round earthquake threat, requiring awareness of both hazard types. After a major earthquake, Imperial County residents should expect water service disruption for 24 to 72 or more hours. Storing a minimum of one gallon per person per day for three days — before any event — is the most direct preparedness action households can take.

Regional Context

Imperial County falls 7.8 points above California's typical county risk level, which means the hazard environment here is notably more demanding than the state baseline.

Is your household prepared for Imperial 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 Imperial County, CA?
Imperial County has a FEMA National Risk Index rating of Relatively High, placing it in the 96th 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 Imperial County?
Imperial County is evaluated for five major natural hazard types: earthquake (99th percentile), flooding (94th percentile), wildfire (76th percentile), hurricane (22th percentile), tornado (11th percentile). The highest-risk hazard is earthquake at the 99th 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 Imperial County risk compare to the California average?
Imperial County's composite risk percentile is 96th, compared to the California state average of 89th percentile. The state's overall risk rating is Relatively Moderate. This means Imperial County faces higher natural disaster risk than the typical county in California.
Is Imperial County at risk for earthquake?
Yes, Imperial County's earthquake risk is at the 99th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Imperial County is at the 94th 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 Imperial County higher risk than average?
Imperial County's composite risk score of 96th percentile is above the California state average of 89th percentile. This elevated risk is driven by earthquake exposure (99th percentile), along with flooding 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.