North Slope Borough, Alaska Natural Disaster Risk
FEMA National Risk Index assessment · AK
Very LowComposite Risk Score
National percentile: 15th
North Slope Borough faces very low composite natural disaster risk (NRI Risk Index score 14.8, 15th national percentile), driven primarily by cold wave and winter weather exposure. Expected annual loss across all 18 hazard types is $5M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates North Slope Borough at very low composite risk, with a National Risk Index score of 14.8 out of 100 — placing it in the 15th national percentile and among the lowest-risk counties in the country. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Most of North Slope Borough's expected losses come from cold wave (prolonged spells of dangerously low temperatures) at Medium risk — $4M in expected annual loss and about 9.97 events per year; winter weather (heavy snow, blizzards, and hazardous winter conditions) at Medium risk — $189K in expected annual loss and about 20.10 events per year; and avalanche (fast-moving snow and debris sliding down steep mountain slopes) at Very Low risk — $1K in expected annual loss and about 0.01 events per year. Across all hazards, FEMA estimates $5M in expected annual loss for a population of 11K.
Beyond physical exposure, North Slope Borough has a medium social vulnerability rating (how susceptible the population is to harm) and a very low community resilience rating (its capacity to prepare for and recover from disasters). Both measures sit toward the lower end, indicating relatively modest population sensitivity.
The federal record bears this out: North Slope Borough has received 8 federal disaster declarations since 1986, including 4 for severe storm events and 2 for biological events. The most recent was Covid-19 Pandemic (biological), declared in April 2020.
Among 30 Alaska counties, North Slope Borough ranks #20 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Cold Wave | Medium | 9.97 / yr | $4M |
| Winter Weather | Medium | 20.10 / yr | $189K |
| Avalanche | Very Low | 0.01 / yr | $1K |
| Earthquake | Very Low | 0.03 / yr | $229K |
| Landslide | Very Low | 0.77 / yr | $44 |
| Wildfire | Very Low | 0.00 / yr | $3K |
| Ice Storm | Very Low | 0.01 / yr | $3K |
| Riverine Flood | Very Low | 0.04 / yr | $378K |
| Lightning | Very Low | 16.01 / yr | $3K |
| Tornado | Very Low | 0.00 / yr | $1 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Drought | Very Low | 0.00 / yr | $0 |
| Hail | Very Low | 0.00 / yr | $0 |
| Heat Wave | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Strong Wind | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
North Slope Borough has received 8 federal disaster declarations since 1986, most recently Covid-19 Pandemic in April 2020. Most frequent causes: Severe Storm (4), Biological (2), Coastal Storm (1).
| Declared | Type | Disaster |
|---|---|---|
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| December 2017 | Severe Storm | Severe Storm |
| October 2015 | Coastal Storm | Severe Storm |
| December 2011 | Severe Storm | Severe Winter Storms and Flooding |
| September 2008 | Severe Storm | Severe Storms, Flooding, Landslides, and Mudslides |
| March 2005 | Severe Storm | Severe Winter Storm |
| October 1986 | Flood | Coastal Storm, High Winds & Waves |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for North Slope Borough?
North Slope Borough has a composite FEMA National Risk Index score of 14.8 out of 100, placing it in the Very Low category and the 15th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in North Slope Borough?
The three highest-rated hazards are Cold Wave (Medium, $4M EAL), Winter Weather (Medium, $189K EAL), Avalanche (Very Low, $1K EAL). These account for most of the county's expected annual losses.
How does North Slope Borough compare to other Alaska counties?
North Slope Borough ranks #20 of 30 Alaska counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has North Slope Borough had?
FEMA records 8 federal disaster declarations for North Slope Borough since 1986, most often 4 for severe storm events and 2 for biological events. The most recent was Covid-19 Pandemic, declared in April 2020.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. North Slope Borough's $5M EAL is a statistical average, not a guarantee for any specific year or address.