St. Lawrence County, New York severe weather history spans 460 recorded events between 1954 and 2026. The dominant hazard is thunderstorm wind, accounting for 72.0% of all recorded events. It ranks #1,018 nationally and #30 in New York.
460
Recorded events
1
Direct deaths
13
Direct injuries
$53.6M
Property damage
The record
What the St. Lawrence County, New York severe weather history record shows
Across the archive, St. Lawrence County, New York severe weather history averages 6.4 recorded events a year. The busiest stretch on record is the 2010s, with 143 events logged in that decade alone. Roughly 44 events fall before 1990 and 416 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the St. Lawrence County, New York record is tornado, responsible for 1 direct deaths. The costliest is thunderstorm wind, with $38.8M in reported property damage. In total, 9 distinct hazard types appear in this county archive, each listed with its own dated record below.
By hazard type
Every hazard type recorded in St. Lawrence County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Thunderstorm Wind | 331 | 0 | $38.8M | 75 | 1958–2026 |
| Hail | 72 | 0 | $68K | 2 | 1966–2025 |
| Flash Flood | 17 | 0 | $6.0M | 0 | 1996–2024 |
| Lightning | 13 | 0 | $522K | 0 | 1996–2024 |
| Tornado | 10 | 1 | $878K | F2 | 1954–2024 |
| Flood | 8 | 0 | $7.5M | 0 | 2010–2024 |
| Funnel Cloud | 4 | 0 | $0 | 0 | 2004–2021 |
| Heavy Rain | 4 | 0 | $0 | 0 | 2002–2005 |
| Strong Wind | 1 | 0 | $0 | 0 | 2001–2001 |
Decade by decade
St. Lawrence County, New York severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
11 mapped tornado paths intersect this county: 11 touched down inside it and 0 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 1986-08-15 | EF2 | 1 | 3 | 0.2 mi | Touched down here |
| 1954-09-19 | EF2 | 0 | 0 | 0.1 mi | Touched down here |
| 1989-07-10 | EF1 | 0 | 1 | 1.7 mi | Touched down here |
| 1985-05-31 | EF1 | 0 | 0 | 5.0 mi | Touched down here |
| 1972-08-07 | EF1 | 0 | 0 | 4.9 mi | Touched down here |
| 2024-08-11 | EF0 | 0 | 0 | 0.1 mi | Touched down here |
| 2004-06-09 | EF0 | 0 | 0 | 2.0 mi | Touched down here |
| 2004-06-09 | EF0 | 0 | 0 | 0.2 mi | Touched down here |
| 1993-06-21 | EF0 | 0 | 0 | 0.4 mi | Touched down here |
| 1988-08-09 | EF0 | 0 | 0 | 0.5 mi | Touched down here |
Significant events
Deadliest events on record in St. Lawrence County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Aug 15, 1986 | Tornado | 1 | 3 | $250K | |
| Jul 7, 1998 | Lightning | WADDINGTON | 0 | 3 | $10K |
| Jun 29, 1995 | Thunderstorm Wind | Massena | 0 | 3 | $50K |
| Jun 18, 1990 | Thunderstorm Wind | 0 | 2 | $0 | |
| Jul 10, 1989 | Tornado | 0 | 1 | $25K | |
| Jul 10, 1989 | Thunderstorm Wind | 0 | 1 | $0 |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Heavy rainfall and snowmelt combined to produce flooding across St. Lawrence County. The Grass and St. Regis Rivers were particularly hard hit, and the Oswegatchie and its tributaries continued to run high from flooding in the previous week. Along the St. Regis, two homes were evacuated in Brasher Center, and areas in Winthrop and Brasher Falls were flooded. In Brasher Center, the Main Street Bridge and County Rte 53 were closed. Throughout Stockholm other bridges over the St. Regis were closed due to flooding, and State Rte 420 Extension and Barnage Road were closed. On the Grass River, several cottages were surrounded by water in Madrid along County Route 36. Elsewhere across the county there were numerous roads closed, including Route 184 at Pope Mills.
Emergency Mgmt. reported widespread flash flooding across the area with numerous roads closed or washed out due to severe flash flooding. This included, but was not limited to US Route 11 in numerous locations. Some homes and bridges were also damaged with a few swift water rescues noted. The hardest hit areas were around Canton, Colton, Potsdam and Stockholm.
Numerous flooding across St. Lawrence county as the results of heavy tropical rains (4 to 6+ inches) from Post Tropical Debby. In addition to flash flooding reports, there were numerous inundation, basement and other flooding.
Context
Risk, population and federal disasters
Relatively Low
FEMA NRI risk rating
107,226
Population (ACS)
$122K
Median home value
19
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| Sep 24, 2024 | Tropical Storm | REMNANTS OF TROPICAL STORM DEBBY | DR |
| Aug 29, 2024 | Flood | SEVERE STORM, TORNADOES, AND FLOODING | DR |
| Mar 15, 2023 | Snowstorm | SEVERE WINTER STORM AND SNOWSTORM | DR |
| Nov 20, 2022 | Winter Storm | SEVERE WINTER STORM AND SNOWSTORM | EM |
| Mar 20, 2020 | Biological | COVID-19 PANDEMIC | DR |
| Mar 13, 2020 | Biological | COVID-19 | EM |
Quick answers
Frequently asked
How many severe weather events have been recorded in St. Lawrence County, New York?
460 events are on record between 1954 and 2026, causing 1 direct deaths and $53.6M in property damage.
What is the most common severe weather hazard in St. Lawrence County?
Thunderstorm Wind, with 331 recorded events — 72.0% of everything in the archive for this county.
How many tornadoes have crossed St. Lawrence County?
11 mapped tornado paths intersect the county boundary; 11 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover St. Lawrence County?
19 federal disaster declarations from FEMA include St. Lawrence County, each tied to a specific incident period.
How risky is St. Lawrence County compared with the rest of the country?
FEMA's National Risk Index rates St. Lawrence County as relatively low risk, placing it in the 78 percentile of its state for expected annual loss.
Where does the St. Lawrence County, New York severe weather history data come from?
Every figure is drawn from United States federal public-domain records: NOAA/NCEI Storm Events for the event archive, NOAA SPC SVRGIS for mapped tornado paths, FEMA for disaster declarations and risk ratings, and the U.S. Census for population context. Dates are shown in UTC and recent entries may still be revised by NOAA.
Nearby
Neighbouring counties
- Rockland County 319
- Saratoga County 1,125
- Richmond County 204
- Schenectady County 423
- Rensselaer County 804
- Schoharie County 354
Cite this page
“St. Lawrence County, New York.” Severe Weather History. severeweatherhistory.com/county/new-york/st-lawrence-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.