Jefferson County, New York: Natural Disaster Risk and History
Jefferson County, New York has a Relatively Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 64.0 out of 100, higher than about 64% of US counties, with winter storms, ice storms and strong winds scoring highest of its 18 hazards and $26 million a year in expected losses.
OpenFEMA lists 19 federal disaster declarations that included Jefferson County since 1973, not counting 2 for COVID-19; the latest is DR-4825-NY (Remnants of Tropical Storm Debby, declared 24 September 2024). NOAA's Storm Prediction Center recorded 5 tornadoes touching Jefferson County from 1950 to 2025.
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Population 116,438 Buildings worth $26 billion Area 1,875 sq mi Risk rank in New York 38 of 62 FIPS 36045
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Winter weather | Relatively High | 93.5 | $617,664 | about 4 a year | 764 |
| Ice storm | Relatively Moderate | 81.5 | $501,711 | about once a year | 51 |
| Strong wind | Relatively Moderate | 78.7 | $1.4 million | about once every 1.3 years | 21 |
| Inland flooding | Relatively Moderate | 78.0 | $19 million | about once every 1.1 years | 25 |
| Earthquake | Relatively Low | 71.5 | $952,111 | about once every 592 years | — |
| Cold wave | Relatively Low | 64.5 | $1.8 million | about 4.8 a year | 92 |
| Hurricane | Very Low | 53.2 | $110,810 | about once every 136 years | 4 |
| Landslide | Very Low | 47.5 | $1,273 | about once every 2.4 years | — |
| Lightning | Relatively Low | 46.2 | $222,475 | about 25 a year | 158,215 strikes |
| Heat wave | Very Low | 33.6 | $179,449 | about 1.5 a year | 29 |
| Wildfire | Very Low | 28.0 | $13,582 | rarer than once in 1,000 years | — |
| Tornado | Relatively Low | 27.9 | $484,525 | about once every 7.7 years | 2 |
| Coastal flooding | Very Low | 16.2 | — | about once every 83 years | — |
| Hail | Very Low | 7.6 | $23,702 | about once every 1.7 years | 22 |
| Drought | No Rating | 0.0 | — | — | 0 |
| Avalanche | Not Applicable | — | — | — | — |
| Tsunami | Insufficient Data | — | — | — | — |
| 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 19
Most common: Snowstorm 7, Flood 3, Severe Storm 2, Hurricane 2.
| Decade | Declarations | Incident types |
|---|---|---|
| 1970s | 3 | Snowstorm ×2, Flood |
| 1990s | 5 | Snowstorm ×4, Flood |
| 2000s | 5 | Other ×2, Hurricane, Severe Storm, Fire |
| 2010s | 4 | Severe Storm, Flood, Snowstorm, Hurricane |
| 2020s | 2 | Tropical Storm, Winter Storm |
The last 10
Widest declarations that included Jefferson 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 Debby (2024), 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 5
| Tornadoes touching the county | 5 |
|---|---|
| Strongest-rated | (E)F1 ×2 |
| Peak month | August (3) |
| Deadliest | 28 Aug 1983, F1, 6 mi path, 0 killed, 1 injured |
| Longest path | 28 Aug 1983, F1, 6 mi path, 0 killed, 1 injured |
| Most recent | 9 Sep 2024, unrated, 0.1 mi path |
| Deaths / injuries on those paths | 0 / 1 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 2 | 2 | 0 | 0 | 0 | 0 | 1 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 1 |
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 Jefferson County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Jefferson County (this page) | — | Relatively Low | 64.0 | Winter weather |
| Lewis County | 47 km | Very Low | 24.7 | Ice storm |
| Oswego County | 71 km | Relatively Low | 67.6 | Winter weather |
| St. Lawrence County | 84 km | Relatively Low | 77.9 | Cold wave |
| Oneida County | 97 km | Relatively Moderate | 86.3 | Winter weather |
| Herkimer County | 103 km | Relatively Low | 60.0 | Inland flooding |
Nearest by distance between county centres. Every county in New York, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively Low 28.3 |
|---|---|
| Community resilience | Relatively High 62.9 |
| Community risk factor | 0.96 |
| Expected annual loss, all hazards | $26 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 Jefferson County's main hazards
- Right now: National Weather Service alerts for New York · all official warnings on Global Incident Tracker.
- Winter weather: Power outages now · Carbon monoxide in winter
- Ice storm: Power outages now · Carbon monoxide in winter
- Strong wind: Power outages now
- 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 Jefferson County
What natural disasters is Jefferson County, New York most at risk from?
Jefferson County, New York has a Relatively Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 64.0 out of 100, higher than about 64% of US counties, with winter storms, ice storms and strong winds scoring highest of its 18 hazards and $26 million a year in expected losses.
How many federal disaster declarations has Jefferson County had?
OpenFEMA lists 19 federal disaster declarations that included Jefferson County since 1973, not counting 2 for COVID-19; the latest is DR-4825-NY (Remnants of Tropical Storm Debby, declared 24 September 2024). Another 7 New York declarations were made statewide without a county list.
How many tornadoes have hit Jefferson County?
NOAA's Storm Prediction Center recorded 5 tornadoes touching Jefferson County from 1950 to 2025. The deadliest: 28 Aug 1983, F1, 6 mi path, 0 killed, 1 injured (deaths and injuries are for the whole path).
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.