Graham County, Arizona Natural Disaster Risk
FEMA National Risk Index assessment · AZ
LowComposite Risk Score
National percentile: 65th
Graham County faces low composite natural disaster risk (NRI Risk Index score 64.6, 65th national percentile), driven primarily by heat wave and wildfire exposure. Expected annual loss across all 18 hazard types is $18M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Graham County at low composite risk, with a National Risk Index score of 64.6 out of 100 — placing it in the 65th national percentile and below the national average for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
The county's risk is driven primarily by heat wave (prolonged periods of extreme heat that threaten health and infrastructure) at Medium risk — $5M in expected annual loss and about 4.85 events per year; wildfire (uncontrolled fires that spread across wildland and into communities) at Medium risk — $2M in expected annual loss and about 0.01 events per year; and lightning (electrical discharges from storms that ignite fires and cause casualties) at High risk — $1M in expected annual loss and about 57.83 events per year. Across all hazards, FEMA estimates $18M in expected annual loss for a population of 38K.
Beyond physical exposure, Graham County has a 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.
History supports the rating: Graham County has received 13 federal disaster declarations since 1966, including 7 for flood events and 2 for biological events. The most recent was Covid-19 Pandemic (biological), declared in April 2020.
Among 15 Arizona counties, Graham County ranks #14 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Heat Wave | Medium | 4.85 / yr | $5M |
| Wildfire | Medium | 0.01 / yr | $2M |
| Lightning | High | 57.83 / yr | $1M |
| Drought | Medium | 85.20 / yr | $677K |
| Winter Weather | Medium | 7.08 / yr | $117K |
| Riverine Flood | Low | 1.71 / yr | $9M |
| Avalanche | Very Low | 0.01 / yr | $591 |
| Earthquake | Very Low | 0.00 / yr | $185K |
| Landslide | Very Low | 1.96 / yr | $608 |
| Hail | Very Low | 0.19 / yr | $99K |
| Strong Wind | Very Low | 0.48 / yr | $95K |
| Hurricane | Very Low | 0.02 / yr | $2K |
| Cold Wave | Very Low | 0.02 / yr | $3K |
| Tornado | Very Low | 0.09 / yr | $4K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Ice Storm | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Graham County has received 13 federal disaster declarations since 1966, most recently Covid-19 Pandemic in April 2020. Most frequent causes: Flood (7), Biological (2), Severe Storm (2).
| Declared | Type | Disaster |
|---|---|---|
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| September 2006 | Severe Storm | Severe Storms and Flooding |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| April 2005 | Severe Storm | Severe Storms and Flooding |
| January 1993 | Flood | Severe Storms, Tornadoes & Flooding |
| December 1990 | Flood | Severe Storms & Flooding |
| October 1983 | Flood | Severe Storms & Flooding |
| December 1978 | Flood | Severe Storms & Flooding |
| March 1978 | Flood | Severe Storms & Flooding |
Showing the 10 most recent of 13 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Graham County?
Graham County has a composite FEMA National Risk Index score of 64.6 out of 100, placing it in the Low category and the 65th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Graham County?
The three highest-rated hazards are Heat Wave (Medium, $5M EAL), Wildfire (Medium, $2M EAL), Lightning (High, $1M EAL). These account for most of the county's expected annual losses.
How does Graham County compare to other Arizona counties?
Graham County ranks #14 of 15 Arizona counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Graham County had?
FEMA records 13 federal disaster declarations for Graham County since 1966, most often 7 for flood events and 2 for biological events. The most recent was Covid-19 Pandemic, declared in April 2020.
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. Graham County's $18M EAL is a statistical average, not a guarantee for any specific year or address.