Petersburg Borough, Alaska: Natural Disaster Risk and History
Petersburg Borough, Alaska has a Very Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 15.4 out of 100, higher than about 15% of US counties, with landslides, avalanches and volcanic activity scoring highest of its 18 hazards and $5.1 million a year in expected losses.
OpenFEMA lists 1 federal disaster declaration that included Petersburg Borough since 2021, not counting 2 for COVID-19; the latest is DR-4585-AK (Severe Storm, Flooding, Landslides, and Mudslides, declared 17 February 2021). NOAA's Storm Prediction Center has no tornado on record touching Petersburg Borough from 1950 to 2025.
Live weather alerts for Alaska All official warnings Latest FEMA declarations
Population 3,393 Buildings worth $915 million Area 3,860 sq mi Risk rank in Alaska 19 of 30 FIPS 02195
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Landslide | Relatively High | 99.7 | $3.0 million | about 5.7 a year | — |
| Avalanche | Relatively High | 92.7 | $1.8 million | about once every 15 years | 2 |
| Volcanic activity | Relatively Low | 86.3 | $3,202 | rarer than once in 1,000 years | 3 |
| Winter weather | Relatively Low | 30.9 | $25,954 | about 13 a year | 192 |
| Earthquake | Very Low | 18.3 | $19,996 | about once every 180 years | — |
| Ice storm | Very Low | 14.4 | $7,560 | about once every 67 years | 0 |
| Cold wave | Very Low | 4.0 | $5,609 | about once every 10 years | 1.4 |
| Wildfire | Very Low | 3.4 | $991 | rarer than once in 1,000 years | — |
| Inland flooding | Very Low | 1.0 | $186,991 | about once every 100 years | 0 |
| Lightning | Very Low | 0.4 | $1,479 | about 2.6 a year | 3,645 strikes |
| Tornado | Very Low | 0.3 | — | rarer than once in 1,000 years | 0 |
| Coastal flooding | No Rating | 0.0 | — | — | — |
| Drought | No Rating | 0.0 | — | — | 0 |
| Hail | No Rating | 0.0 | — | — | 0 |
| Strong wind | No Rating | 0.0 | — | — | 0 |
| Heat wave | Insufficient Data | — | — | — | — |
| Hurricane | Not Applicable | — | — | — | — |
| Tsunami | Insufficient Data | — | — | — | — |
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 1
Most common: Mud/Landslide 1.
| Decade | Declarations | Incident types |
|---|---|---|
| 2020s | 1 | Mud/Landslide |
The last 1
Widest declarations that included Petersburg Borough
- Severe Storm, Flooding, Landslides, and Mudslides (2021, DR-4585-AK): 5 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 Petersburg Borough between 1950 and 2025. That does not mean one cannot happen.
How Petersburg Borough compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Petersburg Borough (this page) | — | Very Low | 15.4 | Landslide |
| Wrangell City and Borough | 105 km | Very Low | 0.1 | Landslide |
| Prince of Wales-Hyder Census Area | 143 km | Very Low | 1.0 | Landslide |
| Sitka City and Borough | 144 km | Very Low | 23.8 | Landslide |
| Juneau City and Borough | 165 km | Very Low | 11.5 | Landslide |
| Hoonah-Angoon Census Area | 208 km | Very Low | 14.3 | Landslide |
Nearest by distance between county centres. Every county in Alaska, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively Moderate 59.5 |
|---|---|
| Community resilience | Very Low 18.7 |
| Community risk factor | 1.24 |
| Expected annual loss, all hazards | $5.1 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 Petersburg Borough's main hazards
- Right now: National Weather Service alerts for Alaska · all official warnings on Global Incident Tracker.
- Landslide: Landslides recorded
- Avalanche: Official warnings now
- Volcanic activity: US volcano alerts
- 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 Petersburg Borough
What natural disasters is Petersburg Borough, Alaska most at risk from?
Petersburg Borough, Alaska has a Very Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 15.4 out of 100, higher than about 15% of US counties, with landslides, avalanches and volcanic activity scoring highest of its 18 hazards and $5.1 million a year in expected losses.
How many federal disaster declarations has Petersburg Borough had?
OpenFEMA lists 1 federal disaster declaration that included Petersburg Borough since 2021, not counting 2 for COVID-19; the latest is DR-4585-AK (Severe Storm, Flooding, Landslides, and Mudslides, declared 17 February 2021). Another 24 Alaska declarations were made statewide without a county list.
How many tornadoes have hit Petersburg Borough?
NOAA's Storm Prediction Center has no tornado on record touching Petersburg 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.