Tornadoes · United States · New York

Tornadoes in St. Lawrence County, New York

12 tornadoes have crossed St. Lawrence County since 1950, 1 of them surveyed so far this year and still preliminary, 15th of the 61 counties in New York with a tornado on record, an average of one every 6.3 years. They have killed 1 person and injured 4. None was rated F4 or above.

The rating scale

Tracks are drawn in the color of the rating. The United States rated tornadoes on Ted Fujita’s F scale until 31 January 2007 and on the Enhanced Fujita scale after it. Both run from 0 to 5, and both rate the damage rather than measure the wind: the speeds are what that damage is taken to imply.

  1. F0 / EF040 to 72 mph on the F scale, 65 to 85 mph on the EF scale

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F1 / EF173 to 112 mph on the F scale, 86 to 110 mph on the EF scale

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2 / EF2113 to 157 mph on the F scale, 111 to 135 mph on the EF scale

    Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

  4. F3 / EF3158 to 206 mph on the F scale, 136 to 165 mph on the EF scale

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4 / EF4207 to 260 mph on the F scale, 166 to 200 mph on the EF scale

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5 / EF5261 to 318 mph on the F scale, over 200 mph on the EF scale

    Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

  7. Unrated

    The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

Now

Tornadoes
12
Deaths
1
Injuries
4
F4 and above
0
Worst on record
F2, August 15, 1986

The deadliest in St. Lawrence County

The strongest

Every year with a tornado

The 11 years of the 76 in the record with a tornado in St. Lawrence County. Each year links to every tornado in New York that year.

YearTornadoesDeathsInjuriesStrongest
20261EF0
20241EF0
20042F0
19931F0
198911F1
19881F0
19871F0
1986113F2
19851F1
19721F1
19541F2

Every tornado that crossed St. Lawrence County

12 tornadoes, newest first. The 1 at the top is this year's, from the surveying office rather than SPC's published database, and its rating is marked as preliminary.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 29, 20266:07 PM EDTEF0St. Lawrence0.140
August 11, 20242:18 PM EDTEF0St. Lawrence0.120
June 9, 20044:40 PM EDTF0St. Lawrence0.2100$30,000
June 9, 20044:15 PM EDTF0St. Lawrence2.0350$30,000
June 21, 199311:20 AM EDTF0St. Lawrence0.420$5,000 to $50,000
July 10, 19895:20 AM EDTF1St. Lawrence1.7301$5,000 to $50,000
August 9, 198810:30 PM EDTF0St. Lawrence0.517$500 to $5,000
July 24, 19874:35 PM EDTF0St. Lawrence0.410$50,000 to $500,000
August 15, 19866:30 PM EDTF2St. Lawrence0.21013$50,000 to $500,000
May 31, 198510:30 PM EDTF1St. Lawrence5.050$50,000 to $500,000
August 7, 19722:00 PM EDTF1St. Lawrence4.930$5,000 to $50,000
September 19, 19547:30 PM GMT-4F2St. Lawrence0.110$5,000 to $50,000

Nearby

Warnings in force in St. Lawrence CountyThe forecast for St. Lawrence CountyThe live radar over St. Lawrence CountyEvery county in New York

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.