Tornadoes · United States · Wisconsin · 1971

F1 tornado, Saint Croix County, Wisconsin, June 4, 1971

Name: F1 tornado, Saint Croix County, Wisconsin, June 4, 1971
Start: 1971-06-05T01:40:00.000Z
Location: Saint Croix County, Wisconsin

This F1 tornado ran 3.8 miles across Saint Croix County on June 4, 1971, touching down at 8:40 PM CDT and reaching 100 yards wide. It killed nobody, and did $5,000 to $50,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

F040 to 72 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
F173 to 112 mphthis tornado
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
F2113 to 157 mph
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.
F3158 to 206 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
F4207 to 260 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
F5261 to 318 mph
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.
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.

The record

Rating: F1
Date: June 4, 1971
Touchdown: 8:40 PM CDT (01:40 UTC)
Path length: 3.8 miles (6.1 km)
Path width: 100 yards (91 m)
Deaths: 0
Injuries: 0
Property damage: $5,000 to $50,000
County: Saint Croix County
Touchdown point: 44.950, -92.500
Lift-off point: 45.000, -92.430
Record number: 417

The surface observations

St. Paul (STP), 47 km from the path, in the two hours either side.

Time (UTC)	Temp (°F)	Dew point (°F)	Wind	Gust (kt)	Pressure (mb)	Weather
00:00 UTC

From the Iowa Environmental Mesonet's archive of airport observations.

This ground now

The live radar over the track Every 1971 tornado in Wisconsin Every tornado in Wisconsin since 1950 Warnings in force in Wisconsin now The forecast where you are

The other tornadoes of June 4, 1971

16 more were confirmed in the United States that day.

Date	Time	Rating	Where	Path (mi)	Width (yd)	Damage
June 4	2:30 PM MDT	F2	Morton, ND	0.5	27	$500 to $5,000
June 4	4:15 PM CDT	F0	Hamilton, NE	5.9	10	$5,000 to $50,000
June 4	4:30 PM CDT	F2	Lyman, SD	0.1	10
June 4	4:45 PM CDT	F2	Jones, SD	0.1	10	$5,000 to $50,000
June 4	5:00 PM CDT	F2	Mellette, SD	0.3	50
June 4	5:11 PM CDT	F0	Polk, NE	0.1	10
June 4	6:23 PM CDT	F2	Marion, MS	0.5	10	$50,000 to $500,000
June 4	7:00 PM CDT	F2	Charles Mix, SD	4.3	137	$5,000 to $50,000
June 4	8:00 PM CDT	F1	Charles Mix, SD	0.1	10	$500 to $5,000
June 4	8:27 PM CDT	F0	Day, SD	0.1	10
June 4	8:30 PM CDT	F1	Adams, NE	13.7	10	$5,000 to $50,000
June 4	9:05 PM CDT	F0	Kingsbury, SD	0.1	10
June 4	9:15 PM CDT	F1	Stutsman, ND	0.8	90	$500 to $5,000
June 4	9:15 PM CDT	F0	Hall, NE	0.1	10	$5,000 to $50,000
June 4	9:30 PM CDT	F1	York, NE	47.4	10	$50,000 to $500,000
June 4	11:35 PM CDT	F1	Jewell, KS	1.5	50	$500 to $5,000

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.