Petersburg Borough, AK: home risks and climate
FEMA’s National Risk Index rates Petersburg Borough “Very Low” for overall risk relative to other US counties, 19th of 30 counties in Alaska by risk score. The hazards rated Relatively High or Very High here are landslide and avalanche. These are relative ratings, not probabilities.
Petersburg Borough, AK
- Watch for new cracks in the ground, tilting trees or fences, and doors that stick.
- Keep gutters and drains directing water away from slopes.
- Know the signs of a debris flow during heavy rain.
- Know whether your home or access road crosses avalanche paths.
- Follow local avalanche center forecasts in winter.
- Keep supplies for being snowed in for several days.
- Clean gutters so melting snow drains instead of forming ice dams.
- Check attic insulation and air sealing; warm attics cause ice dams.
- Keep a snow shovel, ice melt and a backup heat plan.
- Know if you are in a lahar or ashfall zone.
- Keep N95 masks and goggles for ash.
- Have a plan to protect the HVAC system from ash.
- Look up your FEMA flood zone, and remember that "minimal hazard" zones still flood.
- Raise or move valuables, the furnace and the water heater off a basement floor where you can.
- Test the sump pump and its backup before the wet season.
- Pick the safe room: lowest floor, interior, no windows. Tell everyone in the house.
- Keep shoes, a flashlight and a helmet for each person there.
- Turn on wireless emergency alerts on every phone.
- Use surge protection for electronics; ask an electrician about a whole-home surge protector.
- Keep trees near the house healthy and trimmed.
- Unplug sensitive electronics before a storm if you can.
- Clear dead leaves and needles from gutters, the roof and under decks.
- Keep the first 5 feet around the house free of anything that burns (mulch, firewood, plants).
- Cover vents with 1/8-inch metal mesh to keep embers out.
- Know where the main water shutoff is and that it turns.
- Insulate pipes in unheated crawlspaces, garages and exterior walls.
- Have the heating system checked before winter.
- Trim limbs that could fall on the house or the service drop.
- Plan for a multi-day power outage: heat, water, phone charging.
- If you own a generator, know how to run it outdoors safely.
- Strap the water heater to the wall with two straps.
- Secure tall furniture and TVs to studs.
- Know how to shut off gas at the meter, and only do it if you smell gas.
Winterize outdoor faucets before ~Oct 17. Typical first 32°F night (50% date) at Petersburg 1, 34 km away. Last freeze ~Apr 29.
Radon Zone 3: lowest predicted indoor radon. EPA recommends testing every home, whatever the zone.
- This monthPress the test button on every smoke and CO alarm.
- This monthCheck the date on the back of every smoke and CO alarm.
- This monthLook under every sink and around toilets and the water heater for drips.
- This monthClean gutters and downspouts after the leaves are down.
- This monthGet winter gear ready: roof rake, shovel, ice melt and a backup heat plan.
- WatchLook in the attic with a flashlight after the first big storm of the season.
What the records say
Plain-language summary of the numbers below, compared with Alaska and the US.
By FEMA’s hazard scores (0 to 100, the share of US counties scoring lower), landslide scores 99.7 and avalanche scores 92.7 in Petersburg Borough, and modeled expected annual losses from all hazards come to about $5.1 million a year across 3,393 residents.
There have been 3 federal disaster declarations covering Petersburg Borough in the OpenFEMA record, close to the Alaska county median of 4 and below the national county median of 20; 3 came in the last ten years. The most recent was severe storm, flooding, landslides, and mudslides (2021-02-17).
Petersburg Borough sits in climate zone 6A (cold-humid) in the cold Building America region and EPA radon zone 3.
At Petersburg 1 (34 km from the county’s center), the typical first 32°F night is around Oct 17 and the last around Apr 29 (50% dates, 1991–2020), which sets when to winterize outdoor faucets.
All 18 hazards
FEMA National Risk Index December 2025. Ratings and scores are relative to other US counties, not probabilities. Expected annual loss is FEMA’s modeled average across buildings, people and agriculture.
| Hazard | Risk rating | Risk score | Expected annual loss | Recorded events | Prepare |
|---|---|---|---|---|---|
| Landslide | Relatively High | 99.7 | $3.0M | — | Checklist |
| Avalanche | Relatively High | 92.7 | $1.8M | 2 | Checklist |
| Volcanic activity | Relatively Low | 86.3 | $3,202 | 3 | Checklist |
| Winter weather | Relatively Low | 30.9 | $25,954 | 192 | Checklist |
| Earthquake | Very Low | 18.3 | $19,996 | — | Checklist |
| Ice storm | Very Low | 14.4 | $7,560 | 0 | Checklist |
| Cold wave | Very Low | 4.0 | $5,609 | 1 | Checklist |
| Wildfire | Very Low | 3.4 | $991 | — | Checklist |
| Inland flooding | Very Low | 1.0 | $186,991 | 0 | Checklist |
| Lightning | Very Low | 0.4 | $1,479 | 3,645 | Checklist |
| Tornado | Very Low | 0.3 | $0 | 0 | Checklist |
| Coastal flooding | No Rating | 0.0 | $0 | — | Checklist |
| Strong wind | No Rating | 0.0 | $0 | 0 | Checklist |
| Hail | No Rating | 0.0 | $0 | 0 | Checklist |
| Drought | No Rating | 0.0 | $0 | 0 | Checklist |
| Hurricane | Not Applicable | — | — | — | Checklist |
| Heat wave | Insufficient Data | — | — | — | Checklist |
| Tsunami | Insufficient Data | — | — | — | Checklist |
Federal disaster declarations
Each county-level declaration in OpenFEMA DisasterDeclarationsSummaries v2, counted once per disaster number.
| Declared | Event | Type |
|---|---|---|
| 2021-02-17 | Severe storm, flooding, landslides, and mudslides | DR · Mud/Landslide |
| 2020-04-09 | COVID-19 pandemic | DR · Biological |
| 2020-03-13 | COVID-19 | EM · Biological |
Flood-insurance claims (NFIP)
Claims filed under the National Flood Insurance Program, from FEMA’s NfipClaims v3 dataset (all years on file), by year of loss.
Climate, radon and freeze
This month’s plan for Petersburg Borough
Region tasks plus this county’s hazard ratings and freeze dates. Add your ZIP and systems on the Home Plan page to subscribe in your calendar.
November7 tasks
- This monthPress the test button on every smoke and CO alarm.
An alarm you have not heard in months may have a dead battery or sensor. NFPA recommends testing smoke alarms at least once a month.
How
Hold the test button until it sounds. Anything silent or chirping: replace the battery, or the whole alarm if it is past its date.
- This monthCheck the date on the back of every smoke and CO alarm.
Smoke alarms wear out: NFPA advises replacing them 10 years after the manufacture date. CO alarms have their own end-of-life date printed on them.
How
Twist each alarm off its base and read the date. Replace any past its life; swap batteries in alarms that take them.
- This monthLook under every sink and around toilets and the water heater for drips.
Slow leaks rot cabinets and subfloors long before they show. Catching one early is a washer, not a floor.
How
Use a flashlight: feel supply lines and the shutoff valves, look for stains, warped cabinet floors or a toilet that rocks.
- This monthClean gutters and downspouts after the leaves are down.
Blocked gutters overflow at the foundation, rot fascia and, in cold climates, help ice dams form.
How
From a stable ladder (with a helper), scoop debris, then flush each downspout with a hose. Extensions should drop water 4 to 6 feet from the house.
- This monthGet winter gear ready: roof rake, shovel, ice melt and a backup heat plan.
The first storm empties hardware-store shelves.
How
Choose ice melt rated for your walkway material, and plan a safe backup heat source in case of a long outage.
- WatchLook in the attic with a flashlight after the first big storm of the season.
Stains on the roof deck, wet insulation or daylight around vents show leaks early, and droppings show pests.
How
Stay on the joists. Look around chimneys, vent pipes and valleys, the places most leaks start.
- WatchStock a power-outage kit: flashlights, batteries, water, a battery radio.
Winter storms bring multi-day outages.
How
Keep it in one bin. Add a phone power bank and a list of medicines that need power or refrigeration.
December3 tasks
- This monthPress the test button on every smoke and CO alarm.
An alarm you have not heard in months may have a dead battery or sensor. NFPA recommends testing smoke alarms at least once a month.
How
Hold the test button until it sounds. Anything silent or chirping: replace the battery, or the whole alarm if it is past its date.
- This monthKeep the furnace and water-heater intake and exhaust vents clear of snow.
High-efficiency appliances vent through plastic pipes on the side wall. If drifting snow blocks them the appliance shuts down, or exhaust can back up.
How
After each storm, clear the pipes and a foot around them. Keep CO alarms working on every level.
- WatchDegrease the range-hood filter.
Grease-clogged hood filters stop pulling smoke and grease out of the kitchen and can feed a stovetop fire.
How
Pop the metal filter out and soak it in hot water with dish soap and baking soda, or run it through the dishwasher if the maker allows.
Neighbouring counties
Information, not insurance, legal or engineering advice. Ratings describe the county as a whole; your address can differ. Found an error? Send a correction.