Lewis County, New York: Natural Disaster Risk and History
Lewis County, New York has a Very Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 24.7 out of 100, higher than about 24% of US counties, with ice storms, winter storms and landslides scoring highest of its 18 hazards and $9.1 million a year in expected losses.
OpenFEMA lists 26 federal disaster declarations that included Lewis County since 1977, not counting 2 for COVID-19; the latest is DR-4839-NY (Severe Storm and Flooding, declared 21 October 2024). NOAA's Storm Prediction Center recorded 8 tornadoes touching Lewis County from 1950 to 2025.
Live weather alerts for New York All official warnings Latest FEMA declarations
Population 26,548 Buildings worth $7.5 billion Area 1,305 sq mi Risk rank in New York 59 of 62 FIPS 36049
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Ice storm | Relatively Moderate | 73.6 | $294,213 | about once every 1.4 years | 50 |
| Winter weather | Relatively Moderate | 69.0 | $136,207 | about 42 a year | 801 |
| Landslide | Very Low | 53.4 | $1,848 | about once every 1.6 years | — |
| Inland flooding | Relatively Low | 49.9 | $7.3 million | about once a year | 29 |
| Hurricane | Very Low | 47.4 | $63,605 | about once every 171 years | 4 |
| Earthquake | Very Low | 46.9 | $254,997 | about once every 592 years | — |
| Strong wind | Relatively Low | 32.6 | $354,177 | about once every 1.1 years | 36 |
| Cold wave | Relatively Low | 26.0 | $379,752 | about 5.2 a year | 98 |
| Lightning | Very Low | 23.6 | $89,469 | about 26 a year | 69,963 strikes |
| Tornado | Very Low | 17.2 | $201,296 | about once every 7.5 years | 6 |
| Heat wave | Very Low | 15.4 | $41,296 | about 1.2 a year | 22 |
| Wildfire | Very Low | 13.5 | $4,951 | rarer than once in 1,000 years | — |
| Hail | Very Low | 7.1 | $22,035 | about once a year | 39 |
| Drought | No Rating | 0.0 | — | — | 0 |
| Avalanche | Not Applicable | — | — | — | — |
| Coastal flooding | Not Applicable | — | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic activity | Not Applicable | — | — | — | — |
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 26
Most common: Snowstorm 9, Severe Storm 6, Flood 4, Hurricane 3.
| Decade | Declarations | Incident types |
|---|---|---|
| 1970s | 2 | Snowstorm ×2 |
| 1980s | 1 | Flood |
| 1990s | 6 | Snowstorm ×4, Severe Storm, Flood |
| 2000s | 8 | Snowstorm ×2, Severe Storm ×2, Other ×2, Hurricane, Fire |
| 2010s | 5 | Severe Storm ×2, Snowstorm, Hurricane, Flood |
| 2020s | 4 | Severe Storm, Flood, Winter Storm, Hurricane |
The last 10
Widest declarations that included Lewis County
- Hurricane Sandy (2012, EM-3351-NY): 62 New York counties designated.
- Hurricane Katrina Evacuation (2005, EM-3262-NY): 62 New York counties designated.
- Severe Storms and Flooding (2004, DR-1534-NY): 62 New York counties designated.
Named storms in its declarations: Tropical Storm Fred (2021), Hurricane Sandy (2012), Hurricane Katrina (2005).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. New York also had 7 statewide declarations with no county list.
Tornado record since 1950 8
| Tornadoes touching the county | 8 |
|---|---|
| Strongest-rated | (E)F3 ×1 |
| Peak month | August (4) |
| Deadliest | — |
| Longest path | 7 Aug 2023, EF3, 16 mi path |
| Most recent | 7 Aug 2023, unrated, 0.9 mi path |
| Deaths / injuries on those paths | 0 / 0 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 3 | 3 | 0 | 1 | 0 | 0 | 1 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 0 | 1 | 0 | 1 | 0 | 2 | 2 | 2 |
Deaths and injuries are for each tornado's whole path, which can run beyond this county. F-scale ratings before February 2007, Enhanced Fujita (EF) after.
How Lewis County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Lewis County (this page) | — | Very Low | 24.7 | Ice storm |
| Jefferson County | 47 km | Relatively Low | 64.0 | Winter weather |
| Herkimer County | 56 km | Relatively Low | 60.0 | Inland flooding |
| Oneida County | 60 km | Relatively Moderate | 86.3 | Winter weather |
| Oswego County | 69 km | Relatively Low | 67.6 | Winter weather |
| Hamilton County | 78 km | Very Low | 15.1 | Landslide |
Nearest by distance between county centres. Every county in New York, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively Low 28.7 |
|---|---|
| Community resilience | Very High 83.6 |
| Community risk factor | 0.96 |
| Expected annual loss, all hazards | $9.1 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 Lewis County's main hazards
- Right now: National Weather Service alerts for New York · all official warnings on Global Incident Tracker.
- Ice storm: Power outages now · Carbon monoxide in winter
- Winter weather: Power outages now · Carbon monoxide in winter
- Landslide: Landslides recorded
- 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 Lewis County
What natural disasters is Lewis County, New York most at risk from?
Lewis County, New York has a Very Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 24.7 out of 100, higher than about 24% of US counties, with ice storms, winter storms and landslides scoring highest of its 18 hazards and $9.1 million a year in expected losses.
How many federal disaster declarations has Lewis County had?
OpenFEMA lists 26 federal disaster declarations that included Lewis County since 1977, not counting 2 for COVID-19; the latest is DR-4839-NY (Severe Storm and Flooding, declared 21 October 2024). Another 7 New York declarations were made statewide without a county list.
How many tornadoes have hit Lewis County?
NOAA's Storm Prediction Center recorded 8 tornadoes touching Lewis County 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.