Pima County, Arizona: Natural Disaster Risk and History
Pima County, Arizona has a Relatively High natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 99.1 out of 100, higher than about 99% of US counties, with heat waves, wildfires and inland (river and flash) flooding scoring highest of its 18 hazards and $531 million a year in expected losses.
OpenFEMA lists 13 federal disaster declarations that included Pima County since 1966, not counting 2 for COVID-19; the latest is FM-5312-AZ (Big Horn Fire, declared 11 June 2020). NOAA's Storm Prediction Center recorded 28 tornadoes touching Pima County from 1950 to 2025.
Live weather alerts for Arizona All official warnings Latest FEMA declarations
Population 1,042,716 Buildings worth $178 billion Area 9,283 sq mi Risk rank in Arizona 2 of 15 FIPS 04019
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Heat wave | Very High | 99.8 | $133 million | about 8.1 a year | 93 |
| Wildfire | Relatively High | 99.7 | $38 million | about once every 230 years | — |
| Inland flooding | Very High | 99.5 | $347 million | about 13 a year | 359 |
| Lightning | Very High | 97.7 | $2.5 million | about 43 a year | 872,290 strikes |
| Hail | Relatively Moderate | 91.8 | $1.8 million | about once every 4.1 years | 9.2 |
| Earthquake | Relatively Moderate | 91.7 | $6.3 million | about once every 68 years | — |
| Strong wind | Relatively Moderate | 82.6 | $1.3 million | about once every 1.3 years | 31 |
| Winter weather | Relatively Moderate | 80.9 | $199,966 | about 1.8 a year | 34 |
| Drought | Relatively Moderate | 69.6 | $458,566 | about 57 a year | 2,821 |
| Landslide | Very Low | 58.7 | $2,235 | about 2.1 a year | — |
| Avalanche | Very Low | 46.3 | $358 | about once every 100 years | 0 |
| Tornado | Relatively Low | 37.5 | $688,346 | about once every 3.8 years | 14 |
| Hurricane | Very Low | 18.7 | $4,770 | about once every 61 years | 9 |
| Cold wave | Very Low | 3.1 | $150 | about once every 877 years | 0 |
| Coastal flooding | Not Applicable | — | — | — | — |
| Ice storm | Not Applicable | — | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic activity | Not Applicable | — | — | — | — |
Score: FEMA's percentile among US counties that face the hazard (higher = more risk). Expected loss: FEMA's modelled average yearly loss to buildings, people (as a statistical value) and crops. How often: FEMA's annualised frequency of the hazard in the county; for some hazards it counts event-days, so it is a rough guide, not a forecast. "Not Applicable" means FEMA does not model that hazard here.
Federal disaster declarations 13
Most common: Flood 8, Fire 3, Severe Storm 1, Hurricane 1.
| Decade | Declarations | Incident types |
|---|---|---|
| 1960s | 1 | Flood |
| 1970s | 4 | Flood ×4 |
| 1980s | 1 | Flood |
| 1990s | 2 | Flood ×2 |
| 2000s | 4 | Fire ×2, Severe Storm, Hurricane |
| 2020s | 1 | Fire |
The last 10
Widest declarations that included Pima County
- Hurricane Katrina Evacuation (2005, EM-3241-AZ): 15 Arizona counties designated.
- Severe Storms, Tornadoes & Flooding (1993, DR-977-AZ): 13 Arizona counties designated.
- Severe Storms & Flooding (1983, DR-691-AZ): 11 Arizona counties designated.
Named storms in its declarations: Hurricane Katrina (2005).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. Arizona also had 27 statewide declarations with no county list.
Tornado record since 1950 28
| Tornadoes touching the county | 28 |
|---|---|
| Strongest-rated | (E)F2 ×2 |
| Peak month | July (9) |
| Deadliest | 27 Aug 1964, F2, 0.1 mi path, 2 killed, 9 injured |
| Longest path | 2 Jul 2024, EF1, 3.3 mi path |
| Most recent | 16 Sep 2025, unrated |
| Deaths / injuries on those paths | 3 / 53 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 13 | 10 | 2 | 0 | 0 | 0 | 3 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 1 | 4 | 5 | 2 | 5 | 2 | 3 | 6 |
Deaths and injuries are for each tornado's whole path, which can run beyond this county. F-scale ratings before February 2007, Enhanced Fujita (EF) after.
How Pima County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Pima County (this page) | — | Relatively High | 99.1 | Heat wave |
| Pinal County | 99 km | Relatively Moderate | 93.8 | Heat wave |
| Santa Cruz County | 110 km | Relatively Moderate | 88.3 | Heat wave |
| Maricopa County | 154 km | Very High | 99.9 | Heat wave |
| Cochise County | 194 km | Relatively Moderate | 92.8 | Wildfire |
| Graham County | 201 km | Relatively Low | 64.6 | Heat wave |
Nearest by distance between county centres. Every county in Arizona, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively Moderate 50.9 |
|---|---|
| Community resilience | Relatively Low 20.3 |
| Community risk factor | 1.16 |
| Expected annual loss, all hazards | $531 million |
FEMA scales expected losses up where social vulnerability is high (people who may find it harder to prepare, evacuate or recover) and down where community resilience is high. A factor above 1 raises the risk score. For social vulnerability a high rating is worse; for resilience a high rating is better.
Prepare for Pima County's main hazards
- Right now: National Weather Service alerts for Arizona · all official warnings on Global Incident Tracker.
- Heat wave: Heatstroke warning signs
- Wildfire: US wildfires now · Wildfire smoke: what protects you
- Inland flooding: Flood safety: why shallow water kills · Floods recorded
- Your property's flood zone: FEMA Flood Map Service Center ↗ — this page cannot tell you that.
- Official preparedness guidance: Ready.gov ↗ and your county emergency management office.
What this page shows, and what it misses
FEMA's National Risk Index rates a whole county against every other US county; it is a planning-level estimate for nationwide comparison, not a flood-zone map and not a substitute for a local risk assessment or the risk to one home. Declarations are presidential disaster, emergency and fire management declarations that named this county; state declarations and SBA or USDA designations are not included. Tornadoes are counted when the county is one of up to four listed on the track; 670 tornadoes that crossed a state line carry no county list in NOAA's file and are left out.
Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties - v1.20.0 (December 2025). Retrieved from https://services.arcgis.com/XG15cJAlne2vxtgt/ArcGIS/rest/services/National_Risk_Index_Counties/FeatureServer/0/query on November 2, 2026, 1:20 PM EST. 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).
Federal Emergency Management Agency (FEMA), OpenFEMA Dataset: Disaster Declarations Summaries - v2, retrieved from https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries on November 2, 2026, 1:21 PM EST. This product uses the Federal Emergency Management Agency's OpenFEMA API, 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).
Tornado records: NOAA/NWS Storm Prediction Center, Severe Weather Database, tornadoes 1950–2025 (https://www.spc.noaa.gov/wcm/data/1950-2025_actual_tornadoes.csv, downloaded 2 November 2026). Public domain; not endorsed by NOAA. Compiled by Global Incident Tracker.
Questions about Pima County
What natural disasters is Pima County, Arizona most at risk from?
Pima County, Arizona has a Relatively High natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 99.1 out of 100, higher than about 99% of US counties, with heat waves, wildfires and inland (river and flash) flooding scoring highest of its 18 hazards and $531 million a year in expected losses.
How many federal disaster declarations has Pima County had?
OpenFEMA lists 13 federal disaster declarations that included Pima County since 1966, not counting 2 for COVID-19; the latest is FM-5312-AZ (Big Horn Fire, declared 11 June 2020). Another 27 Arizona declarations were made statewide without a county list.
How many tornadoes have hit Pima County?
NOAA's Storm Prediction Center recorded 28 tornadoes touching Pima County from 1950 to 2025. The deadliest: 27 Aug 1964, F2, 0.1 mi path, 2 killed, 9 injured (deaths and injuries are for the whole path).
Is the National Risk Index a flood zone map?
No. The National Risk Index is a planning-level estimate for a whole county, built for nationwide comparison. It does not tell you the flood zone or the risk of a single property: for that, look up the address on FEMA's Flood Map Service Center (msc.fema.gov) and ask your local floodplain manager.