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Natural hazard risk in Maricopa County, Arizona

Updated October 30, 2026. Based on FEMA, NOAA and OpenFEMA data. Published by Humblebee.

FEMA overall Risk Index rating: Very High (score 99.8 of 100)[5]

Expected annual loss (FEMA)
$2.20 billion[1]
Federal disaster declarations since 1966
24[2]
NFIP flood claims paid, 1978 to 2026
$26.1 million[3]
Tornadoes recorded, 1950 to 2024
72[4]

FEMA's National Risk Index (December 2025) rates the overall natural hazard risk for Maricopa County, Arizona, Very High relative to all US counties[5]. Within the county, the hazards with the highest FEMA scores are heat wave, inland flooding and wildfire[6].

FEMA risk ratings for each hazard

Ratings and expected losses from the FEMA National Risk Index. Each rating compares this county with all US counties for that hazard, from Very Low to Very High. They are planning estimates, not predictions, and they do not describe any single property.

FEMA's National Risk Index rates Expected Annual Loss from all 18 natural hazards in Maricopa County Very High[1]. This is a FEMA estimate of average yearly loss, not money anyone paid. FEMA rates both heat wave and inland flooding Very High for risk and for Expected Annual Loss[7][8]. FEMA rates social vulnerability Relatively Low, which describes how susceptible social groups are to harm from hazards[9]. FEMA rates community resilience Very Low, which describes a community's ability to prepare for, withstand and recover from hazards[10].

Hazards sorted by FEMA hazard-type Risk Index score, highest first
HazardFEMA risk ratingExpected annual loss
Heat WaveVery High$958.0 million[7]
Inland FloodingVery High$1.12 billion[8]
WildfireRelatively High$42.2 million[11]
HailVery High$24.2 million[12]
Strong WindVery High$8.8 million[13]
DroughtRelatively High$4.6 million[14]
EarthquakeRelatively Moderate$30.7 million[15]
LightningRelatively High$2.1 million[16]
TornadoRelatively Moderate$5.4 million[17]
LandslideRelatively Low$28,000[18]
Winter WeatherRelatively Low$47,000[19]
AvalancheVery Low$144[20]
HurricaneVery Low$12,000[21]

Rated Not Applicable by FEMA for this county: coastal flooding, ice storm, tsunami, volcanic activity[22].

Social vulnerability and community resilience

FEMA uses these two ratings to scale expected losses into the Risk Index.

FEMA measureRatingScore
Social vulnerabilityRelatively Low27.0[9]
Community resilienceVery Low18.0[10]

Flooding and flood insurance

FEMA rates inland flooding risk in Maricopa County Very High relative to all US counties[8]. OpenFEMA data as of 2026-08-03 show 8,889 residential flood insurance contracts in force out of 1,510,831 residential structures[23]. Inside FEMA's mapped Special Flood Hazard Area there were 20,901 residential structures and 6,086 contracts[23]. A HazardFacts tally of OpenFEMA records counts 2,633 NFIP claims for losses from 1978 to 2026, and 1,741 of them had a payment[3].

Measure Value
Inland Flooding, FEMA risk rating[8] Very High, $1.12 billion expected loss a year
NFIP residential flood policies in force (2026)[23] 8,889 of 1,510,831 homes
Homes in FEMA's mapped high-risk flood area (SFHA)[23] 20,901, of which 6,086 insured
NFIP flood claims, 1978 to 2026[3] 2,633 filed, $26.1 million paid

Is a specific address in a flood zone? Only FEMA's flood maps answer that, property by property[24]. This page describes the whole county.

Search an address on the FEMA Flood Map Service Center

Disaster declarations and tornado records

OpenFEMA lists 24 federal disaster declarations for natural hazards that include Maricopa County since 1966, including 11 for fire and 9 for flood[2]. The most recent was FM-5501-AZ for the Boulder View Fire, declared 2024-06-28[25]. NOAA's Storm Prediction Center tornado database records 72 tornadoes that touched the county from 1950 to 2024, and the strongest were rated F3[4]. The most recent recorded tornado was on 2020-07-24[4].

Federal disaster declarations for natural hazards that include Maricopa County, since 1966
Incident type Declarations
Fire[2] 11
Flood[2] 9
Severe Storm[2] 3
Hurricane[2] 1
Most recent declarations
Declaration Incident Declared
FM-5501-AZ[25] Boulder View Fire 2024-06-28
FM-5496-AZ[25] Rose Fire 2024-06-12
FM-5466-AZ[25] Diamond Fire 2023-06-28
FM-5315-AZ[25] Avondale Fire 2020-06-27
FM-5314-AZ[25] Aquila Fire 2020-06-23

How to prepare

Steps from Ready.gov, FEMA's preparedness site, for the hazards with the highest FEMA ratings here. Follow instructions from local officials and the National Weather Service when a warning is issued.

Extreme heat

Before

  • Learn the signs of heat illness and how to respond.
  • Do not rely on a fan as your main way to stay cool. Fans do not lower body temperature.
  • Find cool public places, such as libraries or malls, or ask your local health department.
  • Keep heat out with window shades, weather stripping and insulation.
  • If you cannot afford cooling costs, contact LIHEAP for help.

During

  • Never leave a person or an animal in a parked car in warm weather.
  • If your home has no air conditioning, go to a cooling center.
  • Wear light, loose clothing, drink plenty of fluids and avoid hard outdoor work in the middle of the day.

Source: Ready.gov, extreme heat

Floods

Before

  • Check your flood risk with FEMA's Flood Map Service Center, and remember that floods do not follow map lines.
  • Sign up for your community's warning system. NOAA Weather Radio also broadcasts alerts.
  • Buy flood insurance through the NFIP well before a disaster. Homeowners policies do not cover flooding, and a new policy typically takes up to 30 days to go into effect.
  • Make a household plan with evacuation routes, shelter locations and what to do in a flash flood.
  • Keep important documents in a waterproof container and make password-protected digital copies.

During

  • If you are told to evacuate, leave right away and never drive around barricades.
  • Do not walk, swim or drive through floodwater. Six inches of moving water can knock you down.
  • If you are trapped in a building, go to the highest level, but do not climb into a closed attic.

Source: Ready.gov, floods

Wildfires

Before

  • Sign up for community alerts and watch for air quality alerts.
  • Make sure everyone knows the evacuation plan, including for school, work and other places you go often.
  • Keep a fire-resistant zone of at least 30 feet around your home, clear of leaves and debris.
  • Use fire-resistant building materials and keep a hose long enough to reach every part of your property.
  • Pick a room you can seal off from outside air and keep a portable air cleaner ready.

During

  • Leave right away when authorities tell you to evacuate.
  • If you are trapped, call 9-1-1 with your location and turn on lights to help rescuers find you.
  • If you are not ordered to leave but there is smoke, stay in a safe indoor place or go to a community building with less smoke.

Source: Ready.gov, wildfires

Questions people ask

Is Maricopa County at risk of flooding?
FEMA rates inland flooding risk in Maricopa County Very High relative to all US counties[8]. OpenFEMA lists 9 flood declarations that include the county since 1966[2].
How do I check if an address in Maricopa County is in a flood zone?
Look up the address on FEMA's Flood Map Service Center or ask the local floodplain manager[24]. County-level ratings do not tell you the flood zone of a single address[24].
Is Maricopa County at risk of wildfire?
FEMA rates wildfire risk in Maricopa County Relatively High relative to all US counties[11]. OpenFEMA lists 11 fire declarations that include the county since 1966[2].
Does Maricopa County get tornadoes?
NOAA's Storm Prediction Center tornado database records 72 tornadoes that touched Maricopa County from 1950 to 2024[4]. FEMA rates tornado risk Relatively Moderate relative to all US counties[17].
How many federal disasters have been declared in Maricopa County?
OpenFEMA lists 24 federal disaster declarations for natural hazards that include Maricopa County since 1966[2]. Of these, 12 were major disaster declarations and 12 were emergency or fire management declarations[2].

Facts and sources

  1. FEMA National Risk Index (version 1.20, December 2025): Expected Annual Loss from all 18 natural hazards in Maricopa County is $2.20 billion a year (Expected Annual Loss rating Very High, score 99.8). Of this, buildings account for $1.20 billion, injuries and deaths (converted to dollars by FEMA) for $988.7 million... FEMA National Risk Index
  2. OpenFEMA Disaster Declarations Summaries list 24 federal disaster declarations for natural hazards that include Maricopa County since 1966 (12 major disaster, 12 emergency or fire management). By incident type: fire 11, flood 9, severe storm 3, hurricane 1. Biological (such as COVID-19) and other non-natural... OpenFEMA Disaster Declarations
  3. HazardFacts tally of OpenFEMA NFIP Redacted Claims (losses from 1978 to 2026): 2,633 National Flood Insurance Program claims were filed for losses in Maricopa County, 1,741 of them with a payment, and NFIP paid $26.1 million in total (building, contents and increased cost of compliance, in dollars of the year... OpenFEMA NFIP claims
  4. NOAA Storm Prediction Center tornado database (1950 to 2024): 72 recorded tornadoes touched Maricopa County. The strongest were rated F3 (most recent of them on 1957-08-04). 1 were rated F3/EF3 or stronger. The most recent recorded tornado was on 2020-07-24. Ratings used the Fujita scale until early 2007 and the... NOAA Storm Prediction Center
  5. FEMA National Risk Index (version 1.20, December 2025): the overall natural hazard Risk Index rating for Maricopa County is Very High, with a Risk Index score of 99.8 out of 100. The score is the county's percentile rank among all US counties. FEMA National Risk Index
  6. Among the 18 hazards in the FEMA National Risk Index (version 1.20, December 2025), the hazards with the highest hazard-type Risk Index scores for Maricopa County are heat wave (100.0, Very High), inland flooding (99.8, Very High), wildfire (99.6, Relatively High). HazardFacts sorted FEMA's published scores; FEMA's... FEMA National Risk Index
  7. FEMA National Risk Index (version 1.20, December 2025), heat wave in Maricopa County: Risk Index rating Very High (score 100.0 of 100). Expected Annual Loss $958.0 million a year (rating Very High). Annualized frequency 19.83 event-days per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  8. FEMA National Risk Index (version 1.20, December 2025), inland flooding in Maricopa County: Risk Index rating Very High (score 99.8 of 100). Expected Annual Loss $1.12 billion a year (rating Very High). Annualized frequency 8.46 event-days per year, from recorded occurrences over a period of record of 26 years. FEMA National Risk Index
  9. FEMA National Risk Index (version 1.20, December 2025): Social Vulnerability rating for Maricopa County is Relatively Low (score 27.0). FEMA describes social vulnerability as how susceptible social groups are to the harm natural hazards cause. FEMA National Risk Index
  10. FEMA National Risk Index (version 1.20, December 2025): Community Resilience rating for Maricopa County is Very Low (score 18.0). FEMA describes community resilience as a community's ability to prepare for, withstand and recover from hazards. FEMA National Risk Index
  11. FEMA National Risk Index (version 1.20, December 2025), wildfire in Maricopa County: Risk Index rating Relatively High (score 99.6 of 100). Expected Annual Loss $42.2 million a year (rating Relatively High). FEMA's modeled annual frequency is 0.0019 events per year. FEMA National Risk Index
  12. FEMA National Risk Index (version 1.20, December 2025), hail in Maricopa County: Risk Index rating Very High (score 99.5 of 100). Expected Annual Loss $24.2 million a year (rating Very High). Annualized frequency 0.28 events per year, from recorded occurrences over a period of record of 37 years. FEMA National Risk Index
  13. FEMA National Risk Index (version 1.20, December 2025), strong wind in Maricopa County: Risk Index rating Very High (score 99.0 of 100). Expected Annual Loss $8.8 million a year (rating Very High). Annualized frequency 1.4 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  14. FEMA National Risk Index (version 1.20, December 2025), drought in Maricopa County: Risk Index rating Relatively High (score 97.7 of 100). Expected Annual Loss $4.6 million a year (rating Relatively High). Annualized frequency 62.54 event-days per year, from recorded occurrences over a period of record of 22 years. FEMA National Risk Index
  15. FEMA National Risk Index (version 1.20, December 2025), earthquake in Maricopa County: Risk Index rating Relatively Moderate (score 96.8 of 100). Expected Annual Loss $30.7 million a year (rating Relatively High). FEMA's modeled annual frequency is 0.0107 events per year. FEMA National Risk Index
  16. FEMA National Risk Index (version 1.20, December 2025), lightning in Maricopa County: Risk Index rating Relatively High (score 95.4 of 100). Expected Annual Loss $2.1 million a year (rating Relatively High). Annualized frequency 32.26 events per year, from recorded occurrences over a period of record of 24 years. FEMA National Risk Index
  17. FEMA National Risk Index (version 1.20, December 2025), tornado in Maricopa County: Risk Index rating Relatively Moderate (score 84.0 of 100). Expected Annual Loss $5.4 million a year (rating Relatively Moderate). Annualized frequency 0.57 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  18. FEMA National Risk Index (version 1.20, December 2025), landslide in Maricopa County: Risk Index rating Relatively Low (score 83.9 of 100). Expected Annual Loss $28,000 a year (rating Relatively Low). FEMA National Risk Index
  19. FEMA National Risk Index (version 1.20, December 2025), winter weather in Maricopa County: Risk Index rating Relatively Low (score 38.7 of 100). Expected Annual Loss $47,000 a year (rating Relatively Low). Annualized frequency 0.57 events per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  20. FEMA National Risk Index (version 1.20, December 2025), avalanche in Maricopa County: Risk Index rating Very Low (score 32.8 of 100). Expected Annual Loss $144 a year (rating Very Low). Annualized frequency 0.01 events per year, from recorded occurrences over a period of record of 28 years. FEMA National Risk Index
  21. FEMA National Risk Index (version 1.20, December 2025), hurricane in Maricopa County: Risk Index rating Very Low (score 26.5 of 100). Expected Annual Loss $12,000 a year (rating Very Low). Annualized frequency 0.01 events per year, from recorded occurrences over a period of record of 172 years for the Atlantic... FEMA National Risk Index
  22. FEMA National Risk Index (version 1.20, December 2025) rates these hazards Not Applicable for Maricopa County: coastal flooding, ice storm, tsunami, volcanic activity. FEMA uses Not Applicable when its source data has no historical record of the hazard in the community and the hazard is not considered... FEMA National Risk Index documentation
  23. NFIP Residential Penetration Rates (OpenFEMA, as of 2026-08-03): 8,889 residential flood insurance contracts were in force in Maricopa County, out of 1,510,831 residential structures, a penetration rate of 0.6%. Inside FEMA's mapped Special Flood Hazard Area there were 20,901 residential structures and 6,086... OpenFEMA NFIP penetration rates
  24. FEMA's Flood Map Service Center is the official public source for flood maps (Flood Insurance Rate Maps) produced under the National Flood Insurance Program. Flood zones apply to specific properties: look up an address there or ask the local floodplain manager. County-level ratings do not tell you the flood zone of... FEMA Flood Map Service Center
  25. Most recent federal disaster declarations for natural hazards (table on this page). OpenFEMA Disaster Declarations

FEMA's National Risk Index compares each county with all other US counties. Ratings are relative (Very Low to Very High), not a measure of safety. Never call a place safe, unsafe, good or bad to live in. Risk Index and Expected Annual Loss values are FEMA estimates for planning. They do not predict next year's losses and do not apply to a single property. Flood zones are set by FEMA flood maps for specific properties. County ratings and flood insurance counts do not tell anyone whether an address is in a flood zone. Disaster declaration, NFIP and tornado counts are records of the past for this county only. Do not compare with other counties unless a fact does.

Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties, v1.20 (December 2025). Retrieved from fema.maps.arcgis.com on October 30, 2026. This product uses the Federal Emergency Management Agency's National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s). This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.