Matanuska-Susitna Borough, AK: home risks and climate
FEMA’s National Risk Index rates Matanuska-Susitna Borough “Relatively Moderate” for overall risk relative to other US counties, 2nd of 30 counties in Alaska by risk score. The hazards rated Relatively High or Very High here are avalanche, earthquake and winter weather. These are relative ratings, not probabilities.
Matanuska-Susitna Borough, AK
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- Photograph the roof and siding now, so you have a dated before picture.
- Ask about impact-rated (UL 2218 Class 4) shingles when the roof is replaced.
- Know your policy’s wind and hail deductible in dollars.
- 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.
- Find out whether your home is in a tsunami hazard zone.
- Know the walking route to high ground.
- Strong shaking near the coast means move to high ground now.
- 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.
Winterize outdoor faucets before ~Sep 16. Typical first 32°F night (50% date) at Talkeetna Airport, 31 km away. Last freeze ~May 16.
Radon Zone 2: moderate 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), avalanche scores 99.9, earthquake scores 98.9 and winter weather scores 93.1 in Matanuska-Susitna Borough, and modeled expected annual losses from all hazards come to about $161.0 million a year across 107,000 residents.
There have been 20 federal disaster declarations covering Matanuska-Susitna Borough in the OpenFEMA record, above the Alaska county median of 4 and close to the national county median of 20; 9 came in the last ten years. The most recent was severe storm (2026-04-07).
Matanuska-Susitna Borough is part of the Anchorage, AK metropolitan area.
Flood-insurance (NFIP) records list 87 claims in Matanuska-Susitna Borough, above the Alaska county median of 59, 10 of them in the last ten years. Of claims with a recorded zone, 41% were outside the mapped high-risk flood zone.
Matanuska-Susitna Borough sits in climate zone 7 (very cold) in the very cold Building America region and EPA radon zone 2.
At Talkeetna Airport (31 km from the county’s center), the typical first 32°F night is around Sep 16 and the last around May 16 (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 |
|---|---|---|---|---|---|
| Avalanche | Very High | 99.9 | $15.4M | 40 | Checklist |
| Earthquake | Relatively High | 98.9 | $130.6M | — | Checklist |
| Winter weather | Relatively High | 93.1 | $620,241 | 209 | Checklist |
| Landslide | Relatively Moderate | 96.8 | $304,065 | — | Checklist |
| Wildfire | Relatively Moderate | 94.7 | $3.8M | — | Checklist |
| Cold wave | Relatively Low | 61.4 | $1.8M | 75 | Checklist |
| Lightning | Relatively Low | 54.8 | $329,405 | 106,687 | Checklist |
| Inland flooding | Relatively Low | 51.3 | $8.2M | 0 | Checklist |
| Volcanic activity | Very Low | 80.8 | $915 | 6 | Checklist |
| Ice storm | Very Low | 17.0 | $14,214 | 0 | Checklist |
| Tsunami | Very Low | 9.2 | $55,953 | 67 | Checklist |
| Hail | Very Low | 3.2 | $7,517 | 0 | Checklist |
| Tornado | Very Low | 0.9 | $7 | 0 | Checklist |
| Coastal flooding | No Rating | 0.0 | $0 | — | Checklist |
| Strong wind | No Rating | 0.0 | $0 | 0 | Checklist |
| Drought | No Rating | 0.0 | $0 | 35 | Checklist |
| Hurricane | Not Applicable | — | — | — | Checklist |
| Heat wave | Insufficient Data | — | — | — | Checklist |
Federal disaster declarations
Each county-level declaration in OpenFEMA DisasterDeclarationsSummaries v2, counted once per disaster number.
| Declared | Event | Type |
|---|---|---|
| 2026-04-07 | Severe storm | DR · Winter Storm |
| 2022-03-14 | Severe winter storm and straight-line winds | DR · Severe Storm |
| 2020-04-09 | COVID-19 pandemic | DR · Biological |
| 2020-03-13 | COVID-19 | EM · Biological |
| 2019-08-22 | Deshka landing fire | FM · Fire |
| 2019-08-20 | Mckinley fire | FM · Fire |
| 2019-01-31 | Earthquake | DR · Earthquake |
| 2018-11-30 | Earthquake | EM · Earthquake |
| 2018-09-05 | Flooding | DR · Flood |
| 2015-06-15 | Sockeye fire | FM · Fire |
| 2012-11-27 | Severe storm, straight-line winds, flooding, and landslides | DR · Severe Storm |
| 2009-06-11 | Flooding and ice jams | DR · Flood |
Showing the 12 most recent of 20.
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.
Inside vs outside the mapped high-risk zone
By the rated flood zone recorded on each claim. Claims outside the high-risk zone are a reminder that “minimal hazard” is not “no hazard”. Check your own zone with an address in the Snapshot.
Climate, radon and freeze
This month’s plan for Matanuska-Susitna 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.