Navajo County, Arizona Natural Disaster Risk
FEMA National Risk Index assessment · AZ
MediumComposite Risk Score
National percentile: 88th
Navajo County faces medium composite natural disaster risk (NRI Risk Index score 88.1, 88th national percentile), driven primarily by lightning and wildfire exposure. Expected annual loss across all 18 hazard types is $40M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Navajo County carries a medium composite natural disaster risk, with a National Risk Index score of 88.1 out of 100 — placing it in the 88th national percentile and near the national midpoint for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Most of Navajo County's expected losses come from lightning (electrical discharges from storms that ignite fires and cause casualties) at Very High risk — $3M in expected annual loss and about 47.60 events per year; wildfire (uncontrolled fires that spread across wildland and into communities) at High risk — $12M in expected annual loss and about 0.00 events per year; and winter weather (heavy snow, blizzards, and hazardous winter conditions) at Very High risk — $522K in expected annual loss and about 5.79 events per year. Across all hazards, FEMA estimates $40M in expected annual loss for a population of 107K.
Beyond physical exposure, Navajo County has a very high social vulnerability rating (how susceptible the population is to harm) and a very low community resilience rating (its capacity to prepare for and recover from disasters). That combination — a more vulnerable population with limited resilience — can amplify the human cost of any given event.
The county's disaster history tells the same story: Navajo County has received 21 federal disaster declarations since 1970, including 7 for flood events and 6 for fire events. The most recent was Severe Storms and Flooding (flood), declared in September 2021.
Among 15 Arizona counties, Navajo County ranks #11 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Lightning | Very High | 47.60 / yr | $3M |
| Wildfire | High | 0.00 / yr | $12M |
| Winter Weather | Very High | 5.79 / yr | $522K |
| Landslide | Medium | 2.54 / yr | $57K |
| Riverine Flood | Medium | 4.14 / yr | $20M |
| Earthquake | Low | 0.00 / yr | $1M |
| Cold Wave | Medium | 0.02 / yr | $1M |
| Ice Storm | Medium | 0.01 / yr | $86K |
| Heat Wave | Low | 0.77 / yr | $281K |
| Volcanic Activity | Very Low | 0.00 / yr | $9 |
| Drought | Low | 102.78 / yr | $92K |
| Avalanche | Very Low | 0.01 / yr | $325 |
| Strong Wind | Low | 0.06 / yr | $231K |
| Hail | Low | 0.11 / yr | $80K |
| Tornado | Very Low | 0.39 / yr | $25K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Disaster History
Navajo County has received 21 federal disaster declarations since 1970, most recently Severe Storms and Flooding in September 2021. Most frequent causes: Flood (7), Fire (6), Severe Storm (4).
| Declared | Type | Disaster |
|---|---|---|
| September 2021 | Flood | Severe Storms and Flooding |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| March 2010 | Severe Storm | Severe Winter Storms and Flooding |
| January 2010 | Severe Storm | Severe Winter Storm |
| September 2006 | Severe Storm | Severe Storms and Flooding |
| June 2006 | Fire | Potato Fire |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| February 2005 | Severe Storm | Severe Storms and Flooding |
| July 2003 | Fire | Kinishba Fire |
Showing the 10 most recent of 21 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Navajo County?
Navajo County has a composite FEMA National Risk Index score of 88.1 out of 100, placing it in the Medium category and the 88th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Navajo County?
The three highest-rated hazards are Lightning (Very High, $3M EAL), Wildfire (High, $12M EAL), Winter Weather (Very High, $522K EAL). These account for most of the county's expected annual losses.
How does Navajo County compare to other Arizona counties?
Navajo County ranks #11 of 15 Arizona counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Navajo County had?
FEMA records 21 federal disaster declarations for Navajo County since 1970, most often 7 for flood events and 6 for fire events. The most recent was Severe Storms and Flooding, declared in September 2021.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Navajo County's $40M EAL is a statistical average, not a guarantee for any specific year or address.