Arizona Environment & Hazard Risk
3 counties rated high or very high risk. 16,957 storm events since 1996, #36 among states.
- Expected yearly loss
- $3.6B
- $504 per person
- Storm events since 1996
- 16,957
- Most often flash flood
- Flood insurance policies
- 17,476
- $61.92M in claims paid
- Superfund sites
- 13
- 309 toxic release facilities
Risk by county
FEMA National Risk Index rating, highest risk first
| County | Overall risk | Top hazard | Flood policies | Flood claims paid |
|---|---|---|---|---|
| Maricopa County | Very High | Heat wave | 8,889 | $26.09M |
| Pima County | High | Heat wave | 2,620 | $7.87M |
| Mohave County | High | Wildfire | 568 | $1.87M |
| Coconino County | Moderate | Lightning | 733 | $5.25M |
| Pinal County | Moderate | Heat wave | 839 | $3.46M |
| Yavapai County | Moderate | Wildfire | 1,396 | $6.31M |
| Cochise County | Moderate | Wildfire | 728 | $641K |
| Yuma County | Moderate | Earthquake | 372 | $1.05M |
| Gila County | Moderate | Wildfire | 268 | $3.54M |
| Santa Cruz County | Moderate | Heat wave | 272 | $1.29M |
| Navajo County | Moderate | Lightning | 328 | $971K |
| La Paz County | Moderate | Heat wave | 212 | $1.05M |
| Apache County | Low | Lightning | 29 | $18.33K |
| Graham County | Low | Heat wave | 209 | $355K |
| Greenlee County | Very Low | Wildfire | 13 | $2.16M |
Costliest hazards
Expected annual loss in Arizona, all counties combined
- Heat wave$1.18B/yr · 7 counties high
- Wildfire$228M/yr · 11 counties high
- Earthquake$103M/yr · 1 county high
- Hail$29.07M/yr · 1 county high
- Lightning$28.71M/yr · 12 counties high
- Strong wind$14.39M/yr · 1 county high
- Drought$11M/yr · 2 counties high
- Tornado$7.81M/yr
- Cold wave$5.41M/yr
- Winter weather$3.31M/yr · 6 counties high
Storm events by type
Since 1996: 3,197 deaths, $4.43B in property and crop damage
- Flash Flood3,609 · 118 deaths
- Thunderstorm Wind3,371 · 4 deaths
- Excessive Heat1,892 · 1,556 deaths
- Hail1,109 · 3 deaths
- High Wind975 · 5 deaths
- Heavy Snow920 · 7 deaths
- Heat814 · 1,342 deaths
- Dust Storm781 · 22 deaths
- Heavy Rain702 · 7 deaths
- Drought633
- Flood406 · 12 deaths
- Winter Storm332 · 22 deaths
Events per year
Most damaging storms
Since 2017, ranked by deaths, injuries and damage
- Excessive Heat07/11/2023
Central Phoenix
150 deaths
What happened
A total of 150 heat-associated fatalities (94 direct and 56 indirect) were reported by the Maricopa County Department of Public Health, with their details, such as age, gender, circumstances, and exact location unavailable.
- Excessive Heat07/23/2023
Central Phoenix
46 deaths
What happened
A total of 46 heat-associated fatalities (17 direct and 29 indirect) were reported by the Maricopa County Department of Public Health, with their details, such as age, gender, circumstances, and exact location unavailable.
- Excessive Heat08/12/2020
Central Phoenix
43 deaths
What happened
Forty-three heat-associated fatalities were reported by the Maricopa County Department of Public Health, with their details, such as age, gender, circumstances and location unavailable.
- Excessive Heat07/14/2023
Tucson Metro Area
40 deaths
What happened
Very hot temperatures of 6 to 13 degrees above normal caused the Major Heat Risk category to be reached across eastern Pima County July 14-29. Record highs at Tucson International Airport included 112 degrees on July 20 and 25 (also reached 112 July 18-19); 111 on July 16, 17 and 21; and 110 on the 15th. A total of 40 heat-related fatalities were reported by the Pima County Medical Examiner. Heat was determined to be the primary cause of death for 13 individuals in Tucson, one in Oro Valley, and one near Sahuarita. Seven of these deaths occurred outdoors while eight individuals were found indoors with A/C units which were either not working, turned off or not present at all. Heat was determined to be a contributing factor for 25 individuals, in Tucson or the immediate vicinity. Twelve of these included the complicating factor of drug toxicity (10 outdoors and 2 indoors with a nonfunctioning A/C). Ten in Tucson suffered from various health issues (2 outdoors and 8 indoors with a nonfunctioning A/C). Heat was a contributing factor for an additional three individuals who had other health issues, one each in Green Valley, Sahuarita and Vail.
- Excessive Heat07/11/2023
East Valley
36 deaths
What happened
A total of 36 heat-associated fatalities (26 direct and 10 indirect) were reported by the Maricopa County Department of Public Health, with their details, such as age, gender, circumstances, and exact location unavailable.
- Excessive Heat06/12/2021
Central Phoenix
35 deaths
What happened
Thirty-five fatalities (27 direct and 8 indirect) were reported by the Maricopa County Department of Public Health, with their details, such as age, gender, circumstances, and exact location unavailable.
Hurricanes and tropical storms
Storms whose track crossed the state, newest first
- Hurricane Newton (2016)09/04/2016 · 977 mbCategory 192 mph peak
- Hurricane Nora (1997)09/16/1997 · 950 mbCategory 4132 mph peak
- Hurricane Lester (1992)08/20/1992 · 985 mbCategory 181 mph peak
- Hurricane Raymond (1989)09/25/1989 · 935 mbCategory 4144 mph peak
- Tropical Storm Hyacinth (1968)08/17/1968Tropical storm52 mph peak
- Hurricane Katrina (1967)08/30/1967Category 186 mph peak
- Unnamed storm (1958)09/30/1958Category 186 mph peak
- Unnamed storm (1929)06/27/1929 · Landfall: TX · 982 mbCategory 192 mph peak
Flood insurance
National Flood Insurance Program policies and claims
17,476 homes in Arizona have flood insurance, about 0.7% of residential buildings. In high-risk flood zones, 12,298 of 57,819 homes (21%) are insured.
- Flooding$8.39M · 771 claims
- Arizona Burn Scar Flash Flooding$20.09K · 1 claim
Drinking water
746 community water systems serve about 7,127,230 people
Since 2021, 309 systems reported 1,060 health-based violations. 203 systems had a violation of any kind still open at last report. These had the most:
- Wellton Town ofServes 3,000 · Surface water · Local government33 health violations+96 monitoring or reporting
- Cs Citrus Park Water CompanyServes 102 · Groundwater · Private31 health violations+21 monitoring or reporting
- Papago Butte DwidServes 700 · Groundwater · Private24 health violations+19 monitoring or reporting
- White Horse Ranch Owners AssociationServes 292 · Groundwater · Public and private23 health violations+7 monitoring or reporting
- Green Valley MhpServes 190 · Groundwater · Public and private23 health violations+19 monitoring or reporting
- Maricopa Mountain Dwid 1Serves 450 · Groundwater · Private22 health violations+4 monitoring or reporting
- Cs El Prado Water CompanyServes 404 · Groundwater · Private22 health violations+13 monitoring or reporting
- San Simon DwidServes 312 · Groundwater · Private22 health violations+29 monitoring or reporting
Select a county above to see every system that serves it.
Climate in the largest cities
1991-2020 normals from the nearest NOAA weather station
Pollution sites
13 Superfund sites and 309 toxic release facilities
Superfund sites
- Apache Powder co.Final NPL Site, Saint David
- Hassayampa LandfillFinal NPL Site, Arlington
- Indian Bend Wash AreaFinal NPL Site, Scottsdale
- Iron King Mine - Humboldt SmelterFinal NPL Site, Dewey-Humboldt
- Lukachukai Mountains Mining DistrictFinal NPL Site, Cove
- Motorola, Inc. (52nd Street Plant)Final NPL Site, Phoenix
- Phoenix-Goodyear Airport AreaFinal NPL Site, Goodyear
- Tucson International Airport AreaFinal NPL Site, Tucson
Largest toxic releases
- Asarco LLC Ray Complex/ Hayden Smelter & Concentrator55.0 million lbs, Hayden
- Freeport-Mcmoran Miami Inc27.0 million lbs, Claypool
- Pinto Valley Mine14.2 million lbs, Miami
- Freeport-Mcmoran Morenci Inc6.3 million lbs, Morenci
- Freeport-Mcmoran Bagdad Inc3.0 million lbs, Bagdad
- Freeport-Mcmoran Safford Inc2.3 million lbs, Safford
- Springerville Generating Station2.2 million lbs, Springerville
- Asarco LLC Mission Complex2.1 million lbs, Sahuarita
Facilities in Arizona reported 117.5 million lbs of toxic releases in 2024, 1.6 million lbs of it into the air.
Frequently asked questions
- What is the biggest natural hazard in Arizona?
- By expected annual loss, heat wave costs the most in Arizona ($1.18B a year), according to FEMA's National Risk Index.
- How many storms hit Arizona each year?
- NOAA recorded 16,957 storm events in Arizona since 1996, about 547 a year. The most common type is flash flood.
- How many homes in Arizona have flood insurance?
- 17,476 residential flood insurance policies are in force in Arizona. Since 1978 the National Flood Insurance Program has paid $61.92M on 5,263 claims here.
- How many Superfund sites are in Arizona?
- Arizona has 13 Superfund sites on or deleted from EPA's National Priorities List.
Source: FEMA, NOAA, EPA · Last updated 08/01/2026 · Storm counts include events in forecast zones that touch each county. This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.