Spearfish Micro Area Natural Disasters and Weather Extremes
The chance of earthquake damage in Spearfish Area is about the same as South Dakota average and is much lower than the national average. The risk of tornado damage in Spearfish Area is lower than South Dakota average and is much lower than the national average.
Earthquake Index, #497
| Spearfish Area | 0.04 |
| South Dakota | 0.05 |
| 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, #129
| Spearfish Area | 0.0000 |
| South Dakota | 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, #672
| Spearfish Area | 65.26 |
| South Dakota | 114.73 |
| 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 5,049 other weather extremes events within 50 miles of Spearfish Area 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: | 50 | Cold: | 12 | Dense Fog: | 0 | Drought: | 7 |
| Dust Storm: | 0 | Flood: | 142 | Hail: | 3,071 | Heat: | 3 | Heavy Snow: | 40 |
| High Surf: | 0 | Hurricane: | 0 | Ice Storm: | 2 | Landslide: | 0 | Strong Wind: | 135 |
| Thunderstorm Winds: | 1,353 | Tropical Storm: | 0 | Wildfire: | 28 | Winter Storm: | 74 | Winter Weather: | 3 |
| Other: | 129 | ||||||||
Volcanos Nearby
No volcano is found in or near Spearfish Area.
Historical Earthquake Events
A total of 1 historical earthquake event that had a recorded magnitude of 3.5 or above found in or near Spearfish Area.
| Distance (miles) | Date | Magnitude | Depth (km) | Latitude | Longitude |
| 19.9 | 1966-06-26 | 4.1 | N/A | 44.3 | -103.4 |
Historical Tornado Events
A total of 20 historical tornado events that had recorded magnitude of 2 or above found in or near Spearfish Area.
| Distance (miles) | Date | Magnitude | Start Lat/Log | End Lat/Log | Length | Width | Fatalities | Injuries | Property Damage | Crop Damage | Affected County |
| 6.7 | 1969-07-23 | 2 | 44°18'N / 103°41'W | 0.20 Mile | 33 Yards | 0 | 0 | 0K | 0 | Lawrence | |
| 10.7 | 1965-07-12 | 3 | 44°15'N / 104°03'W | 44°13'N / 103°49'W | 11.40 Miles | 1600 Yards | 0 | 0 | 250K | 0 | Lawrence |
| 14.1 | 1972-06-28 | 2 | 44°33'N / 103°43'W | 0.10 Mile | 33 Yards | 0 | 1 | 3K | 0 | Lincoln | |
| 15.9 | 1968-06-20 | 2 | 44°11'N / 103°56'W | 44°04'N / 103°43'W | 13.10 Miles | 100 Yards | 0 | 0 | 0K | 0 | Lawrence |
| 18.9 | 1965-07-12 | 3 | 44°15'N / 104°15'W | 44°15'N / 104°03'W | 9.40 Miles | 1400 Yards | 0 | 0 | 250K | 0 | Crook |
| 20.9 | 1965-07-18 | 3 | 44°36'N / 103°33'W | 0 | 0 | 25K | 0 | Meade | |||
| 23.9 | 1975-06-25 | 3 | 44°14'N / 104°21'W | 44°22'N / 104°12'W | 11.50 Miles | 440 Yards | 0 | 0 | 25K | 0 | Crook |
| 26.1 | 1953-05-28 | 2 | 43°51'N / 104°19'W | 44°23'N / 104°06'W | 38.20 Miles | 433 Yards | 0 | 0 | 3K | 0 | Weston |
| 29.9 | 2009-07-13 | 2 | 44°35'N / 104°25'W | 44°33'N / 104°14'W | 9.00 Miles | 600 Yards | 0 | 2 | 300K | 0K | Crook |
| Brief Description: EVENT NARRATIVE: A large tornado touched down west of Cook Lake and tracked east-southeastward across the Bear Lodge Mountains, dissipating west of Wyoming Highway 111. The tornado downed about 4000 acres of Ponderosa pine trees, destroyed two metal shop buildings and a large barn at a ranch, and severely damaged a house and mobile home. Two people in the residences received very minor injuries. EPISODE NARRATIVE: A supercell thunderstorm developed over northern Campbell County and moved southeastward across Crook County. The storm produced very large hail across western Crook County, which caused significant damage in the New Haven and Hulett areas. The storm also spawned a large tornado over the Bear Lodge Mountains north of Sundance. | |||||||||||
| 30.6 | 1991-05-11 | 3 | 44°12'N / 103°13'W | 2.00 Miles | 500 Yards | 0 | 20 | 2.5M | 0 | Meade | |
| 31.0 | 1991-05-11 | 2 | 44°11'N / 103°13'W | 1.00 Mile | 300 Yards | 0 | 5 | 250K | 0 | Meade | |
| 31.3 | 1955-09-20 | 2 | 44°43'N / 103°25'W | 1.30 Miles | 177 Yards | 0 | 0 | 3K | 0 | Butte | |
| 31.8 | 1985-05-10 | 2 | 44°10'N / 104°23'W | 1.00 Mile | 27 Yards | 0 | 0 | 3K | 0 | Crook | |
| 33.4 | 1966-07-23 | 2 | 43°58'N / 103°28'W | 43°56'N / 103°23'W | 3.80 Miles | 440 Yards | 0 | 5 | 25K | 0 | Pennington |
| 35.6 | 1967-06-18 | 2 | 44°04'N / 103°12'W | 1.00 Mile | 150 Yards | 0 | 3 | 2.5M | 0 | Pennington | |
| 36.1 | 1959-06-25 | 2 | 44°16'N / 104°31'W | 1.00 Mile | 133 Yards | 0 | 0 | 25K | 0 | Crook | |
| 38.6 | 1961-05-18 | 2 | 44°24'N / 104°35'W | 44°24'N / 104°34'W | 0 | 0 | 25K | 0 | Crook | ||
| 39.3 | 1965-06-11 | 2 | 43°49'N / 103°32'W | 0 | 0 | 3K | 0 | Custer | |||
| 42.0 | 1958-06-12 | 2 | 43°53'N / 104°20'W | 1.00 Mile | 200 Yards | 0 | 0 | 25K | 0 | Weston | |
| 46.4 | 1963-07-18 | 3 | 44°59'N / 103°26'W | 44°57'N / 103°23'W | 2.30 Miles | 33 Yards | 0 | 0 | 250K | 0 | Butte |
* 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.