Lewis County, New York Natural Disaster Risk
FEMA National Risk Index assessment · NY
Very LowComposite Risk Score
National percentile: 25th
Lewis County faces very low composite natural disaster risk (NRI Risk Index score 24.7, 25th national percentile), driven primarily by ice storm and winter weather exposure. Expected annual loss across all 18 hazard types is $9M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Lewis County at very low composite risk, with a National Risk Index score of 24.7 out of 100 — placing it in the 25th 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.
Risk here concentrates in ice storm (freezing rain that coats surfaces in heavy, damaging ice) at Medium risk — $294K in expected annual loss and about 0.73 events per year; winter weather (heavy snow, blizzards, and hazardous winter conditions) at Medium risk — $136K in expected annual loss and about 42.14 events per year; and landslide (downhill movement of rock, soil, and debris on unstable slopes) at Very Low risk — $2K in expected annual loss and about 0.62 events per year. Across all hazards, FEMA estimates $9M in expected annual loss for a population of 27K.
Beyond physical exposure, Lewis County has a low social vulnerability rating (how susceptible the population is to harm) and a very high community resilience rating (its capacity to prepare for and recover from disasters). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
History supports the rating: Lewis County has received 28 federal disaster declarations since 1977, including 9 for snowstorm events and 6 for severe storm events. The most recent was Severe Storm and Flooding (severe storm), declared in October 2024.
Among 62 New York counties, Lewis County ranks #59 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Ice Storm | Medium | 0.73 / yr | $294K |
| Winter Weather | Medium | 42.14 / yr | $136K |
| Landslide | Very Low | 0.62 / yr | $2K |
| Riverine Flood | Low | 1.04 / yr | $7M |
| Hurricane | Very Low | 0.01 / yr | $64K |
| Earthquake | Very Low | 0.00 / yr | $255K |
| Strong Wind | Low | 0.94 / yr | $354K |
| Cold Wave | Low | 5.16 / yr | $380K |
| Lightning | Very Low | 25.77 / yr | $89K |
| Tornado | Very Low | 0.13 / yr | $201K |
| Heat Wave | Very Low | 1.16 / yr | $41K |
| Wildfire | Very Low | 0.00 / yr | $5K |
| Hail | Very Low | 1.04 / yr | $22K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Drought | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Lewis County has received 28 federal disaster declarations since 1977, most recently Severe Storm and Flooding in October 2024. Most frequent causes: Snowstorm (9), Severe Storm (6), Flood (4).
| Declared | Type | Disaster |
|---|---|---|
| October 2024 | Severe Storm | Severe Storm and Flooding |
| August 2024 | Flood | Severe Storm, Tornadoes, and Flooding |
| November 2022 | Winter Storm | Severe Winter Storm and Snowstorm |
| October 2021 | Hurricane | Remnants of Tropical Storm Fred |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| December 2019 | Severe Storm | Severe Storms, Straight-Line Winds, and Flooding |
| December 2014 | Snowstorm | Severe Winter Storm, Snowstorm, and Flooding |
| July 2014 | Severe Storm | Severe Storms and Flooding |
| October 2012 | Hurricane | Hurricane Sandy |
Showing the 10 most recent of 28 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Lewis County?
Lewis County has a composite FEMA National Risk Index score of 24.7 out of 100, placing it in the Very Low category and the 25th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Lewis County?
The three highest-rated hazards are Ice Storm (Medium, $294K EAL), Winter Weather (Medium, $136K EAL), Landslide (Very Low, $2K EAL). These account for most of the county's expected annual losses.
How does Lewis County compare to other New York counties?
Lewis County ranks #59 of 62 New York counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Lewis County had?
FEMA records 28 federal disaster declarations for Lewis County since 1977, most often 9 for snowstorm events and 6 for severe storm events. The most recent was Severe Storm and Flooding, declared in October 2024.
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. Lewis County's $9M EAL is a statistical average, not a guarantee for any specific year or address.