St. Lawrence County, New York: Natural Disaster Risk and History
St. Lawrence County, New York has a Relatively Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 77.9 out of 100, higher than about 77% of US counties, with cold waves, ice storms and winter storms scoring highest of its 18 hazards and $32 million a year in expected losses.
OpenFEMA lists 17 federal disaster declarations that included St. Lawrence County since 1991, 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 11 tornadoes touching St. Lawrence County from 1950 to 2025.
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Population 108,366 Buildings worth $23 billion Area 2,850 sq mi Risk rank in New York 25 of 62 FIPS 36089
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Cold wave | Relatively Moderate | 88.6 | $5.2 million | about 4.6 a year | 87 |
| Ice storm | Relatively High | 87.3 | $606,298 | about once every 1.5 years | 44 |
| Winter weather | Relatively High | 87.2 | $273,982 | about 2 a year | 368 |
| Earthquake | Relatively Low | 86.5 | $2.7 million | about once every 272 years | — |
| Inland flooding | Relatively Moderate | 85.0 | $22 million | about once a year | 27 |
| Lightning | Relatively Moderate | 77.6 | $546,802 | about 24 a year | 152,046 strikes |
| Landslide | Relatively Low | 77.1 | $9,663 | about 2.1 a year | — |
| Hurricane | Relatively Low | 59.2 | $158,001 | about once every 104 years | 4 |
| Heat wave | Very Low | 37.4 | $169,081 | about 1.3 a year | 22 |
| Strong wind | Relatively Low | 35.2 | $293,626 | about once every 1.8 years | 21 |
| Wildfire | Very Low | 33.1 | $14,580 | rarer than once in 1,000 years | — |
| Tornado | Very Low | 24.2 | $285,328 | about once every 10 years | 8 |
| Avalanche | Very Low | 17.8 | $22 | about once every 100 years | 0 |
| Hail | Very Low | 3.6 | $6,178 | about once every 3.0 years | 13 |
| Drought | No Rating | 0.0 | — | — | 0 |
| 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 17
Most common: Snowstorm 6, Flood 3, Hurricane 2, Other 2.
| Decade | Declarations | Incident types |
|---|---|---|
| 1990s | 5 | Snowstorm ×4, Flood |
| 2000s | 5 | Other ×2, Hurricane, Severe Storm, Fire |
| 2010s | 3 | Flood, Snowstorm, Hurricane |
| 2020s | 4 | Tropical Storm, Flood, Snowstorm, Winter Storm |
The last 10
Widest declarations that included St. Lawrence 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 11
| Tornadoes touching the county | 11 |
|---|---|
| Strongest-rated | (E)F2 ×2 |
| Peak month | August (4) |
| Deadliest | 15 Aug 1986, F2, 0.2 mi path, 1 killed, 3 injured |
| Longest path | 31 May 1985, F1, 5 mi path |
| Most recent | 11 Aug 2024, EF0, 0.1 mi path |
| Deaths / injuries on those paths | 1 / 4 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 6 | 3 | 2 | 0 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 1 | 0 | 1 | 5 | 1 | 2 | 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 St. Lawrence County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| St. Lawrence County (this page) | — | Relatively Low | 77.9 | Cold wave |
| Franklin County | 61 km | Relatively Low | 48.9 | Ice storm |
| Jefferson County | 84 km | Relatively Low | 64.0 | Winter weather |
| Lewis County | 85 km | Very Low | 24.7 | Ice storm |
| Hamilton County | 103 km | Very Low | 15.1 | Landslide |
| Essex County | 111 km | Relatively Low | 62.7 | Landslide |
Nearest by distance between county centres. Every county in New York, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively High 64.7 |
|---|---|
| Community resilience | Relatively High 70.4 |
| Community risk factor | 1.25 |
| Expected annual loss, all hazards | $32 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 St. Lawrence County's main hazards
- Right now: National Weather Service alerts for New York · all official warnings on Global Incident Tracker.
- Cold wave: Carbon monoxide in winter · Power outages now
- Ice storm: Power outages now · Carbon monoxide in winter
- Winter weather: Power outages now · Carbon monoxide in winter
- 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 St. Lawrence County
What natural disasters is St. Lawrence County, New York most at risk from?
St. Lawrence County, New York has a Relatively Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 77.9 out of 100, higher than about 77% of US counties, with cold waves, ice storms and winter storms scoring highest of its 18 hazards and $32 million a year in expected losses.
How many federal disaster declarations has St. Lawrence County had?
OpenFEMA lists 17 federal disaster declarations that included St. Lawrence County since 1991, 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 St. Lawrence County?
NOAA's Storm Prediction Center recorded 11 tornadoes touching St. Lawrence County from 1950 to 2025. The deadliest: 15 Aug 1986, F2, 0.2 mi path, 1 killed, 3 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.