Matanuska-Susitna Borough, Alaska: Natural Disaster Risk and History
Matanuska-Susitna Borough, Alaska has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 93.3 out of 100, higher than about 93% of US counties, with avalanches, earthquakes and landslides scoring highest of its 18 hazards and $161 million a year in expected losses.
OpenFEMA lists 18 federal disaster declarations that included Matanuska-Susitna Borough since 1986, not counting 2 for COVID-19; the latest is DR-4904-AK (Severe Storm, declared 7 April 2026). NOAA's Storm Prediction Center has no tornado on record touching Matanuska-Susitna Borough from 1950 to 2025.
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Population 107,000 Buildings worth $33 billion Area 25,521 sq mi Risk rank in Alaska 2 of 30 FIPS 02170
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Avalanche | Very High | 99.9 | $15 million | about 1.3 a year | 40 |
| Earthquake | Relatively High | 98.9 | $131 million | about once every 4.9 years | — |
| Landslide | Relatively Moderate | 96.8 | $304,065 | about 91 a year | — |
| Wildfire | Relatively Moderate | 94.7 | $3.8 million | about once every 901 years | — |
| Winter weather | Relatively High | 93.1 | $620,241 | about 11 a year | 209 |
| Volcanic activity | Very Low | 80.8 | $915 | about once every 48 years | 6 |
| Cold wave | Relatively Low | 61.4 | $1.8 million | about 4 a year | 75 |
| Lightning | Relatively Low | 54.8 | $329,405 | about 18 a year | 106,687 strikes |
| Inland flooding | Relatively Low | 51.3 | $8.2 million | about once every 100 years | 0 |
| Ice storm | Very Low | 17.0 | $14,214 | about once every 67 years | 0 |
| Tsunami | Very Low | 9.2 | $55,953 | about once every 3.3 years | 67 |
| Hail | Very Low | 3.2 | $7,517 | about once every 158 years | 0.2 |
| Tornado | Very Low | 0.9 | $7 | rarer than once in 1,000 years | 0 |
| Coastal flooding | No Rating | 0.0 | — | about once every 83 years | — |
| Drought | No Rating | 0.0 | — | about 1.1 a year | 35 |
| Strong wind | No Rating | 0.0 | — | — | 0 |
| Heat wave | Insufficient Data | — | — | — | — |
| Hurricane | 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 18
Most common: Severe Storm 5, Flood 5, Fire 4, Earthquake 3.
| Decade | Declarations | Incident types |
|---|---|---|
| 1980s | 1 | Flood |
| 1990s | 2 | Fire, Flood |
| 2000s | 6 | Severe Storm ×3, Flood ×2, Earthquake |
| 2010s | 7 | Fire ×3, Earthquake ×2, Flood, Severe Storm |
| 2020s | 2 | Winter Storm, Severe Storm |
The last 10
Widest declarations that included Matanuska-Susitna Borough
- Severe Winter Storms and Avalanches (2000, DR-1316-AK): 15 Alaska counties designated.
- Earthquake (2002, DR-1440-AK): 7 Alaska counties designated.
- Severe Storm, Straight-Line Winds, Flooding, and Landslides (2012, DR-4094-AK): 6 Alaska counties designated.
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. Alaska also had 24 statewide declarations with no county list.
Tornado record since 1950 0
No tornado in NOAA's Storm Prediction Center record touched Matanuska-Susitna Borough between 1950 and 2025. That does not mean one cannot happen.
How Matanuska-Susitna Borough compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Matanuska-Susitna Borough (this page) | — | Relatively Moderate | 93.3 | Avalanche |
| Anchorage Municipality | 133 km | Relatively High | 97.4 | Earthquake |
| Denali Borough | 151 km | Very Low | 28.3 | Avalanche |
| Kenai Peninsula Borough | 251 km | Relatively Moderate | 93.0 | Avalanche |
| Chugach Census Area | 268 km | Very Low | 19.6 | Landslide |
| Copper River Census Area | 294 km | Very Low | 39.9 | Avalanche |
Nearest by distance between county centres. Every county in Alaska, ranked.
Vulnerability and resilience
| Social vulnerability | Very Low 17.2 |
|---|---|
| Community resilience | Very Low 3.7 |
| Community risk factor | 0.88 |
| Expected annual loss, all hazards | $161 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 Matanuska-Susitna Borough's main hazards
- Right now: National Weather Service alerts for Alaska · all official warnings on Global Incident Tracker.
- Avalanche: Official warnings now
- Earthquake: Earthquakes today · Earthquake safety guide
- Landslide: Landslides 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 Matanuska-Susitna Borough
What natural disasters is Matanuska-Susitna Borough, Alaska most at risk from?
Matanuska-Susitna Borough, Alaska has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 93.3 out of 100, higher than about 93% of US counties, with avalanches, earthquakes and landslides scoring highest of its 18 hazards and $161 million a year in expected losses.
How many federal disaster declarations has Matanuska-Susitna Borough had?
OpenFEMA lists 18 federal disaster declarations that included Matanuska-Susitna Borough since 1986, not counting 2 for COVID-19; the latest is DR-4904-AK (Severe Storm, declared 7 April 2026). Another 24 Alaska declarations were made statewide without a county list.
How many tornadoes have hit Matanuska-Susitna Borough?
NOAA's Storm Prediction Center has no tornado on record touching Matanuska-Susitna Borough from 1950 to 2025.
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.