Rock County Natural Disasters and Weather Extremes
Hot Minnesota Rankings
The chance of earthquake damage in Rock County is about the same as Minnesota average and is much lower than the national average. The risk of tornado damage in Rock County is higher than Minnesota average and is higher than the national average.
Earthquake Index, #8
| Rock County | 0.03 |
| Minnesota | 0.01 |
| U.S. | 1.81 |
The earthquake index value is calculated based on historical earthquake events data using USA.com algorithms. It is an indicator of the earthquake level in a region. A higher earthquake index value means a higher chance of an earthquake.
Volcano Index, #1
| Rock County | 0.0000 |
| Minnesota | 0.0000 |
| U.S. | 0.0023 |
The volcano index value is calculated based on the currently known volcanoes using USA.com algorithms. It is an indicator of the possibility of a region being affected by a possible volcano eruption. A higher volcano index value means a higher chance of being affected.
Tornado Index, #16
| Rock County | 188.54 |
| Minnesota | 135.90 |
| U.S. | 136.45 |
The tornado index value is calculated based on historical tornado events data using USA.com algorithms. It is an indicator of the tornado level in a region. A higher tornado index value means a higher chance of tornado events.
Other Weather Extremes Events
A total of 11,816 other weather extremes events within 50 miles of Rock County were recorded from 1950 to 2010. The following is a break down of these events:
| Type | Count | Type | Count | Type | Count | Type | Count | Type | Count |
| Avalanche: | 0 | Blizzard: | 104 | Cold: | 31 | Dense Fog: | 2 | Drought: | 19 |
| Dust Storm: | 0 | Flood: | 837 | Hail: | 5,812 | Heat: | 12 | Heavy Snow: | 99 |
| High Surf: | 0 | Hurricane: | 0 | Ice Storm: | 18 | Landslide: | 0 | Strong Wind: | 135 |
| Thunderstorm Winds: | 4,163 | Tropical Storm: | 0 | Wildfire: | 3 | Winter Storm: | 141 | Winter Weather: | 147 |
| Other: | 293 | ||||||||
Volcanos Nearby
No volcano is found in or near Rock County.
Historical Earthquake Events
A total of 1 historical earthquake event that had a recorded magnitude of 3.5 or above found in or near Rock County.
| Distance (miles) | Date | Magnitude | Depth (km) | Latitude | Longitude |
| 32.7 | 1982-07-11 | 3.6 | 5 | 44.01 | -96.72 |
Historical Tornado Events
A total of 71 historical tornado events that had recorded magnitude of 2 or above found in or near Rock County.
| Distance (miles) | Date | Magnitude | Start Lat/Log | End Lat/Log | Length | Width | Fatalities | Injuries | Property Damage | Crop Damage | Affected County |
| 4.4 | 1956-06-29 | 2 | 43°44'N / 96°16'W | 0 | 0 | 0K | 0 | Rock | |||
| 9.5 | 1969-06-25 | 2 | 43°40'N / 96°25'W | 43°51'N / 96°24'W | 12.30 Miles | 120 Yards | 0 | 5 | 250K | 0 | Rock |
| 12.0 | 2000-07-25 | 2 | 43°38'N / 96°03'W | 43°40'N / 96°00'W | 3.00 Miles | 200 Yards | 0 | 0 | 150K | 0 | Nobles |
| Brief Description: A tornado damaged buildings, vehicles, and trees on a farm. The tornado destroyed the west side of the house, blew three grain bins away and wrapped them around trees. The tornado also blew the top of a barn off, killing at least 4 calves inside. | |||||||||||
| 15.2 | 1978-07-06 | 2 | 43°28'N / 96°24'W | 43°26'N / 96°07'W | 14.20 Miles | 200 Yards | 0 | 0 | 2.5M | 0 | Lyon |
| 16.0 | 1993-05-07 | 2 | 43°28'N / 96°29'W | 43°31'N / 96°27'W | 1.50 Miles | 70 Yards | 0 | 0 | 500K | 0 | Lyon |
| Brief Description: Border Crosser, went into Minnehaha County, SD at 1500CST. Intense thunderstorms developed ahead of an approaching cold front. This line was the first wave of storms to form. The bulk of the severe weather passed to the west and north of Iowa. One very large cell formed over the northwest corner of the state. It produced a tornado northwest of Larchwood, in the northwest corner of Lyon County. Buildings were damaged on three farms. A total of 10 buildings were destroyed as well as two silos. On one of the farms, the owner watched as a 1500 pound fertilizer tank was lifted 50 feet into the air and blew past his window. Total damage to the three farmsteads affected amounted to about $200,000. The only injury that occurred was to a bull on one of the farms. The bull sustained a broken leg. The tornado passed into southeast South Dakota shortly after this damage occurred. It was a border crossing tornado. | |||||||||||
| 16.6 | 1992-06-16 | 5 | 43°48'N / 96°01'W | 43°51'N / 96°00'W | 3.00 Miles | 280 Yards | 0 | 0 | 25.0M | 0 | Nobles |
| 17.5 | 1998-03-29 | 2 | 43°47'N / 95°57'W | 43°47'N / 95°57'W | 0.10 Mile | 75 Yards | 0 | 0 | 400K | 0 | Nobles |
| Brief Description: A tornado destroyed buildings...trees in shelter belts...and numerous pieces of farm equipment...and killed two cattle. | |||||||||||
| 18.6 | 1985-04-20 | 3 | 43°54'N / 96°06'W | 43°55'N / 96°05'W | 0.80 Mile | 250 Yards | 0 | 0 | 2.5M | 0 | Pipestone |
| 19.1 | 1986-04-26 | 2 | 43°21'N / 96°23'W | 43°27'N / 96°19'W | 9.50 Miles | 70 Yards | 0 | 0 | 2.5M | 0 | Lyon |
| 20.2 | 1998-03-29 | 2 | 43°48'N / 95°54'W | 43°48'N / 95°54'W | 0.10 Mile | 75 Yards | 0 | 0 | 200K | 0 | Nobles |
| Brief Description: A tornado destroyed farm buildings...uprooted numerous trees...and overturned a tractor trailer. | |||||||||||
| 21.5 | 1986-04-26 | 2 | 43°24'N / 96°02'W | 43°28'N / 95°56'W | 8.50 Miles | 120 Yards | 1 | 2 | 2.5M | 0 | Lyon |
| 22.0 | 1969-06-25 | 2 | 43°51'N / 96°24'W | 44°06'N / 96°23'W | 17.00 Miles | 120 Yards | 0 | 0 | 250K | 0 | Pipestone |
| 22.2 | 1986-04-26 | 2 | 43°28'N / 95°56'W | 43°35'N / 95°48'W | 10.00 Miles | 40 Yards | 0 | 2 | 2.5M | 0 | Nobles |
| 23.3 | 1985-04-20 | 3 | 43°55'N / 96°05'W | 44°01'N / 96°00'W | 7.20 Miles | 250 Yards | 0 | 2 | 2.5M | 0 | Murray |
| 23.8 | 1992-06-16 | 2 | 43°55'N / 95°59'W | 43°56'N / 95°54'W | 4.00 Miles | 40 Yards | 0 | 0 | 0K | 0 | Murray |
| 24.4 | 1992-06-16 | 5 | 43°51'N / 96°00'W | 44°00'N / 95°51'W | 13.00 Miles | 280 Yards | 1 | 35 | 25.0M | 0 | Murray |
| 24.7 | 2008-06-05 | 2 | 43°43'N / 96°46'W | 43°45'N / 96°44'W | 3.00 Miles | 100 Yards | 0 | 0 | 0K | 0K | Minnehaha |
| Brief Description: EVENT NARRATIVE: A tornado caused damage to silos, farm buildings, power lines, and numerous trees. EPISODE NARRATIVE: Thunderstorms produced numerous events of tornadoes, large hail and damaging winds over southeast South Dakota from late morning through the evening of June 5th. The thunderstorms also produced heavy rain which resulted in flash flooding at several locations. | |||||||||||
| 24.7 | 1954-06-19 | 3 | 43°29'N / 96°43'W | 43°30'N / 96°40'W | 0 | 0 | 3K | 0 | Lincoln | ||
| 24.8 | 1977-05-27 | 2 | 43°28'N / 95°48'W | 43°37'N / 95°48'W | 10.30 Miles | 60 Yards | 0 | 0 | 250K | 0 | Nobles |
| 25.2 | 2010-06-25 | 2 | 43°26'N / 95°57'W | 43°24'N / 95°51'W | 5.00 Miles | 450 Yards | 0 | 0 | 500K | 0K | Lyon |
| Brief Description: EVENT NARRATIVE: A tornado destroyed two hog confinement buildings, killing about 12 hogs, numerous outbuildings, a metal farm building, tore the roof off a house and damaged at least 6 other houses, and caused damage to other farm buildings, power lines, vehicles, and trees, before moving out of Lyon County and into Osceola County. EPISODE NARRATIVE: Thunderstorms produced tornadoes, one that caused considerable damage and at least two injuries along a 14 mile path, along with damaging winds, in northwest Iowa during the evening of June 25th. | |||||||||||
| 25.2 | 1956-05-10 | 2 | 43°37'N / 95°48'W | 43°42'N / 95°43'W | 6.50 Miles | 880 Yards | 0 | 0 | 250K | 0 | Nobles |
| 25.3 | 1987-07-11 | 2 | 43°50'N / 96°44'W | 43°50'N / 96°42'W | 5.00 Miles | 100 Yards | 0 | 0 | 25K | 0 | Minnehaha |
| 26.5 | 1956-08-08 | 2 | 43°33'N / 96°46'W | 0 | 0 | 0K | 0 | Minnehaha | |||
| 27.8 | 1954-06-19 | 2 | 43°17'N / 96°18'W | 43°15'N / 96°15'W | 2.30 Miles | 880 Yards | 0 | 0 | 25K | 0 | Lyon |
| 28.1 | 1992-06-16 | 4 | 43°57'N / 95°54'W | 44°03'N / 95°58'W | 7.00 Miles | 160 Yards | 0 | 3 | 25.0M | 0 | Murray |
| 28.7 | 1964-06-22 | 2 | 43°29'N / 96°50'W | 43°38'N / 96°48'W | 10.00 Miles | 33 Yards | 0 | 0 | 25K | 0 | Lincoln |
| 30.9 | 1965-05-08 | 2 | 43°46'N / 96°49'W | 43°49'N / 96°54'W | 4.50 Miles | 10 Yards | 0 | 0 | 25K | 0 | Clay |
| 31.1 | 1986-04-26 | 2 | 43°18'N / 96°40'W | 43°24'N / 96°44'W | 5.00 Miles | 40 Yards | 0 | 0 | 250K | 0 | Lincoln |
| 31.4 | 2010-06-25 | 4 | 43°24'N / 95°51'W | 43°22'N / 95°42'W | 8.00 Miles | 800 Yards | 0 | 13 | 3.0M | 0K | Osceola |
| Brief Description: EVENT NARRATIVE: A tornado destroyed at least two houses, injuring two people in one of them. the tornado also destroyed several garages and severely damaged several other homes, destroyed at least 4 hog confinement buildings, several barns and silos, and numerous outbuildings. The tornado destroyed three vehicles that had been parked under an Iowa Highway 60 overpass, injuring 11 people in the vehicles, and removing the engine from one of the vehicles. The tornado damaged power lines, causing power outages, and caused damage to trees and crops. The tornado also destroyed a shelter belt and severely damaged heavy farm equipment, removing the wheels from some of the vehicles. Much of the damage occurred a short distance west to south of the town of Sibley. EPISODE NARRATIVE: Thunderstorms produced tornadoes, one that caused considerable damage and at least two injuries along a 14 mile path, along with damaging winds, in northwest Iowa during the evening of June 25th. | |||||||||||
| 32.9 | 1992-06-16 | 2 | 43°59'N / 95°46'W | 0.50 Mile | 30 Yards | 0 | 0 | 0K | 0 | Murray | |
| 33.0 | 1992-06-16 | 2 | 43°47'N / 96°56'W | 43°51'N / 96°51'W | 5.00 Miles | 50 Yards | 0 | 0 | 2.5M | 0 | Minnehaha |
| 33.1 | 1982-06-06 | 2 | 43°24'N / 95°43'W | 2.00 Miles | 67 Yards | 0 | 0 | 2.5M | 0 | Osceola | |
| 33.2 | 2008-05-01 | 2 | 43°08'N / 96°18'W | 43°15'N / 96°22'W | 9.00 Miles | 400 Yards | 0 | 0 | 0.5M | 0K | Sioux |
| Brief Description: EVENT NARRATIVE: A tornado damaged numerous trees, including large trees uprooted, blew windows out of a home, destroyed a metal shed, blew two windows and part of a wall out of a metal building, damaged at least three grain bins, destroyed or damaged numerous outbuildings and small sheds, blew down or snapped off at least 15 power poles, bent a metal light pole, tipped one wagon and blew the top off another, blew down a barb wire fence and pushed fence posts almost to the ground, destroyed a hog barn, and flattened corn stubble, before crossing the county line into Lyon County. Contents inside several damaged or destroyed buildings and sheds were also damaged, especially on one farm where damaged buildings housed a farm and trucking business. EPISODE NARRATIVE: Thunderstorms produced 5 confirmed tornadoes over extreme northwest Iowa during the early evening hours of May 1st. One large long track tornado caused considerable damage, while the other 4 tornadoes were short lived and weak. | |||||||||||
| 33.2 | 1956-06-29 | 2 | 44°00'N / 96°53'W | 44°02'N / 96°34'W | 15.60 Miles | 33 Yards | 0 | 1 | 3K | 0 | Moody |
| 35.8 | 1962-05-12 | 2 | 43°32'N / 96°59'W | 43°41'N / 96°58'W | 10.10 Miles | 880 Yards | 0 | 0 | 25K | 0 | Minnehaha |
| 36.1 | 1992-08-09 | 2 | 43°52'N / 96°56'W | 3.00 Miles | 250 Yards | 0 | 0 | 2.5M | 0 | Lake | |
| 37.8 | 1971-05-31 | 3 | 43°13'N / 95°57'W | 43°30'N / 95°20'W | 36.50 Miles | 100 Yards | 0 | 0 | 0K | 0 | O'brien |
| 38.2 | 1992-06-16 | 2 | 44°00'N / 95°51'W | 44°09'N / 95°38'W | 13.00 Miles | 40 Yards | 0 | 0 | 0K | 0 | Murray |
| 39.5 | 1992-06-16 | 3 | 44°06'N / 95°49'W | 44°12'N / 95°51'W | 9.00 Miles | 80 Yards | 0 | 0 | 0K | 0 | Murray |
| 39.5 | 1970-07-01 | 2 | 43°09'N / 96°36'W | 43°08'N / 96°32'W | 2.30 Miles | 1320 Yards | 0 | 0 | 25K | 0 | Lincoln |
| 39.6 | 1981-06-13 | 2 | 43°10'N / 95°53'W | 0 | 0 | 3K | 0 | Sioux | |||
| 40.1 | 1956-06-29 | 2 | 44°00'N / 96°58'W | 44°00'N / 96°53'W | 3.00 Miles | 33 Yards | 0 | 0 | 3K | 0 | Lake |
| 41.3 | 1966-05-22 | 2 | 43°24'N / 97°00'W | 0 | 0 | 3K | 0 | Turner | |||
| 41.3 | 1965-05-05 | 2 | 43°10'N / 95°29'W | 43°24'N / 95°47'W | 21.80 Miles | 33 Yards | 0 | 0 | 3K | 0 | O'brien |
| 41.7 | 1966-06-02 | 2 | 43°06'N / 96°24'W | 43°02'N / 96°11'W | 11.50 Miles | 300 Yards | 0 | 0 | 25K | 0 | Sioux |
| 42.1 | 1986-04-26 | 2 | 43°16'N / 96°55'W | 43°15'N / 96°51'W | 6.00 Miles | 50 Yards | 0 | 0 | 2.5M | 0 | Lincoln |
| 42.4 | 1981-06-14 | 2 | 43°26'N / 95°33'W | 43°29'N / 95°23'W | 8.80 Miles | 1533 Yards | 0 | 0 | 2.5M | 0 | Osceola |
| 42.8 | 1957-06-10 | 2 | 43°51'N / 97°05'W | 0 | 0 | 0K | 0 | Lake | |||
| 43.0 | 1968-06-13 | 2 | 43°23'N / 95°30'W | 0 | 0 | 250K | 0 | Osceola | |||
| 43.1 | 1981-06-14 | 2 | 43°25'N / 95°33'W | 43°27'N / 95°23'W | 8.30 Miles | 1533 Yards | 0 | 0 | 2.5M | 0 | Osceola |
| 43.1 | 1971-05-31 | 3 | 43°20'N / 95°32'W | 43°27'N / 95°27'W | 8.60 Miles | 250 Yards | 0 | 0 | 250K | 0 | Osceola |
| 43.3 | 1964-06-22 | 2 | 43°07'N / 96°53'W | 43°21'N / 96°53'W | 16.10 Miles | 33 Yards | 0 | 0 | 0K | 0 | Lincoln |
| 44.0 | 1986-04-26 | 2 | 43°14'N / 96°56'W | 43°16'N / 96°55'W | 6.00 Miles | 50 Yards | 0 | 0 | 2.5M | 0 | Turner |
| 44.2 | 2003-06-24 | 2 | 43°14'N / 96°56'W | 43°19'N / 96°59'W | 7.00 Miles | 300 Yards | 0 | 0 | 500K | 0 | Turner |
| Brief Description: A tornado, after crossing into Turner County from Lincoln County, heavily damaged farm buildings, including one farm home demolished, and roof and window damage to at least two other farm homes. The tornado also caused an unknown amount of crop damage. | |||||||||||
| 44.3 | 1970-07-14 | 2 | 43°10'N / 96°48'W | 43°07'N / 96°44'W | 3.80 Miles | 33 Yards | 1 | 1 | 25.0M | 0 | Lincoln |
| 44.4 | 1968-06-13 | 5 | 44°10'N / 95°45'W | 44°12'N / 95°42'W | 2.30 Miles | 150 Yards | 0 | 0 | 2.5M | 0 | Murray |
| 44.7 | 1992-06-16 | 3 | 44°12'N / 95°51'W | 44°14'N / 95°43'W | 3.00 Miles | 80 Yards | 0 | 0 | 0K | 0 | Lyon |
| 45.0 | 1968-09-22 | 3 | 43°01'N / 96°04'W | 43°04'N / 95°59'W | 4.70 Miles | 50 Yards | 0 | 0 | 2.5M | 0 | Sioux |
| 45.4 | 1966-07-09 | 2 | 43°26'N / 95°25'W | 1.00 Mile | 200 Yards | 0 | 0 | 25K | 0 | Osceola | |
| 45.7 | 1987-07-07 | 2 | 43°04'N / 96°37'W | 43°01'N / 96°29'W | 6.00 Miles | 50 Yards | 0 | 0 | 0K | 0 | Union |
| 45.8 | 1979-08-08 | 2 | 43°04'N / 95°53'W | 0.40 Mile | 100 Yards | 0 | 0 | 2.5M | 0 | Sioux | |
| 46.0 | 1964-05-08 | 2 | 43°26'N / 95°26'W | 43°29'N / 95°21'W | 5.10 Miles | 200 Yards | 0 | 0 | 25K | 0 | Osceola |
| 46.8 | 1987-07-07 | 2 | 43°01'N / 96°29'W | 43°00'N / 96°27'W | 2.00 Miles | 50 Yards | 0 | 0 | 250K | 0 | Sioux |
| 47.1 | 1970-06-15 | 3 | 44°09'N / 96°57'W | 44°10'N / 96°54'W | 0 | 0 | 250K | 0 | Lake | ||
| 47.3 | 1955-04-19 | 2 | 44°17'N / 96°09'W | 44°25'N / 96°09'W | 9.20 Miles | 80 Yards | 0 | 0 | 250K | 0 | Lincoln |
| 47.6 | 2003-06-24 | 2 | 43°23'N / 97°08'W | 43°24'N / 97°08'W | 1.50 Miles | 200 Yards | 0 | 0 | 3.0M | 0 | Turner |
| Brief Description: A tornado heavily damaged or destroyed numerous structures at the county fairgrounds, uprooted numerous trees, and blew down power lines, resulting in power outages which lasted up to a day. The tornado damaged other structures in Parker including homes and the county courthouse. One home was shifted off its foundation and received broken windows and damaged siding. Some of the damage resulted from falling trees or wind blown debris. | |||||||||||
| 47.7 | 1978-07-05 | 2 | 43°02'N / 96°15'W | 42°56'N / 96°03'W | 11.90 Miles | 200 Yards | 0 | 0 | 2.5M | 0 | Sioux |
| 48.1 | 2000-07-11 | 2 | 43°58'N / 97°10'W | 43°57'N / 97°07'W | 2.00 Miles | 100 Yards | 0 | 0 | 50K | 0 | Lake |
| Brief Description: A tornado destroyed storage sheds, lighting, fencing, and caused other damage at Lake County Speedway. The tornado also damaged crops over a small area. | |||||||||||
| 49.3 | 1968-06-21 | 2 | 44°24'N / 96°28'W | 44°22'N / 96°08'W | 16.40 Miles | 30 Yards | 0 | 1 | 0K | 0 | Lincoln |
| 49.5 | 1992-06-16 | 2 | 43°57'N / 95°26'W | 44°06'N / 95°22'W | 7.50 Miles | 90 Yards | 0 | 0 | 0K | 0 | Cottonwood |
| 49.7 | 1968-06-13 | 5 | 44°12'N / 95°42'W | 44°16'N / 95°35'W | 6.80 Miles | 150 Yards | 9 | 150 | 2.5M | 0 | Lyon |
* The information on this page is based on the global volcano database, the U.S. earthquake database of 1638-1985, and the U.S. Tornado and Weather Extremes database of 1950-2010.