Natural disaster risk in Arizona, by county
All 15 counties in Arizona, ranked by FEMA's National Risk Index composite risk score, with each one's highest-rated hazard. Other states
At a glance
Highest overall risk: Maricopa County (very high, score 99.9). Lowest: Greenlee County (very low, score 12.4).
Top hazards in Arizona
| Hazard | Counties rated relatively high or very high | Average score |
|---|---|---|
| Lightning | 12 of 15 | 85.2 |
| Wildfire | 11 of 15 | 92.5 |
| Inland (riverine) flooding | 7 of 15 | 86.8 |
| Heat wave | 7 of 15 | 84.6 |
| Winter weather | 6 of 15 | 55.3 |
All counties, highest risk first
| # | County | Overall risk | Highest-rated hazard |
|---|---|---|---|
| 1 | Maricopa County | Very high 99.9 | Heat wave (very high) |
| 2 | Pima County | Relatively high 99.1 | Heat wave (very high) |
| 3 | Mohave County | Relatively high 94.8 | Lightning (very high) |
| 4 | Coconino County | Relatively moderate 94.2 | Lightning (very high) |
| 5 | Pinal County | Relatively moderate 93.8 | Lightning (very high) |
| 6 | Yavapai County | Relatively moderate 93.7 | Lightning (very high) |
| 7 | Cochise County | Relatively moderate 92.8 | Lightning (very high) |
| 8 | Yuma County | Relatively moderate 92.6 | Earthquake (relatively high) |
| 9 | Gila County | Relatively moderate 90.2 | Wildfire (relatively high) |
| 10 | Santa Cruz County | Relatively moderate 88.3 | Heat wave (relatively high) |
| 11 | Navajo County | Relatively moderate 88.1 | Lightning (very high) |
| 12 | La Paz County | Relatively moderate 83.5 | Inland (riverine) flooding (relatively moderate) |
| 13 | Apache County | Relatively low 78.8 | Lightning (very high) |
| 14 | Graham County | Relatively low 64.6 | Lightning (relatively high) |
| 15 | Greenlee County | Very low 12.4 | Lightning (relatively moderate) |
How to read these ratings
- Ratings run in five steps: very low, relatively low, relatively moderate, relatively high and very high. They compare a county with every other US county; they are not a measure of danger on their own.
- Scores run from 0 to 100 and are national percentiles. The bar shows the score: a score of 80 means a higher value than 80% of US counties.
- Overall risk combines the expected annual loss with social vulnerability and community resilience.
- Expected annual loss is the average yearly loss to buildings, people and agriculture the model expects from all 18 hazards.
- Social vulnerability describes how hard it may be for people to prepare for and recover from a disaster. Higher is worse.
- Community resilience describes a community's ability to prepare, adapt and recover. Higher is better.
- "Not applicable" means FEMA does not model that hazard there (for example, hurricanes far inland).
About this data
Source: FEMA National Risk Index, version 1.20, released December 2025, published by the Federal Emergency Management Agency (US public domain). About the National Risk Index. The index is a model of relative risk built from historical hazard records, what is exposed and community factors. It is not a forecast, it does not describe any single property, and it is not insurance or financial advice. For decisions about a specific address, check FEMA's flood maps and your local emergency management office.
Questions
Which county in Arizona has the highest natural disaster risk?
Maricopa County has the highest composite risk score in Arizona in FEMA's National Risk Index: 99.9, rated very high.
Which county in Arizona has the lowest natural disaster risk?
Greenlee County has the lowest composite risk score in Arizona: 12.4, rated very low. A low score means lower modelled risk compared with other US counties, not no risk.
What natural disasters is Arizona most at risk from?
Across Arizona, the hazards rated highest in the most counties are lightning, wildfire, inland (riverine) flooding, according to FEMA's National Risk Index. Each county page lists all 18 hazards.
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