Boulder County Natural Disasters and Weather Extremes
The chance of earthquake damage in Boulder County is lower than Colorado average and is lower than the national average. The risk of tornado damage in Boulder County is higher than Colorado average and is higher than the national average.
Earthquake Index, #8
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, #19
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, #9
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 6,533 other weather extremes events within 50 miles of Boulder County were recorded from 1950 to 2010. The following is a break down of these events:
|Dust Storm:||0||Flood:||304||Hail:||4,459||Heat:||0||Heavy Snow:||43|
|High Surf:||0||Hurricane:||0||Ice Storm:||0||Landslide:||0||Strong Wind:||47|
|Thunderstorm Winds:||993||Tropical Storm:||0||Wildfire:||33||Winter Storm:||35||Winter Weather:||7|
A total of 1 volcano is found in or near Boulder County.
|Distance (miles)||Name||Region||Latitude||Longitude||Elevation (foot)||Type||Status||Last Eruption|
|91.8||Dotsero||US-Colorado, United States||39.65||-107.03||2230||Maar||Radiocarbon||Last known eruption B.C. (Holocene)|
Historical Earthquake Events
A total of 28 historical earthquake events that had recorded magnitudes of 3.5 or above found in or near Boulder County.
|Distance (miles)||Date||Magnitude||Depth (km)||Latitude||Longitude|
Historical Tornado Events
A total of 33 historical tornado events that had recorded magnitude of 2 or above found in or near Boulder County.
|Distance (miles)||Date||Magnitude||Start Lat/Log||End Lat/Log||Length||Width||Fatalities||Injuries||Property Damage||Crop Damage||Affected County|
|11.0||1980-10-15||2||40°01'N / 105°13'W||1.50 Miles||50 Yards||0||0||25K||0||Boulder|
|20.2||1988-06-05||2||39°57'N / 105°04'W||0.50 Mile||50 Yards||0||0||250K||0||Boulder|
|22.8||1988-06-05||2||40°02'N / 104°59'W||40°02'N / 104°58'W||1.00 Mile||50 Yards||0||0||250K||0||Weld|
|23.0||1988-06-05||2||40°00'N / 104°58'W||40°02'N / 104°59'W||1.00 Mile||50 Yards||0||0||250K||0||Adams|
|27.0||1981-06-03||2||39°52'N / 104°59'W||2.30 Miles||133 Yards||0||42||25.0M||0||Adams|
|31.8||1981-06-03||2||39°43'N / 105°03'W||39°44'N / 105°02'W||0||0||2.5M||0||Jefferson|
|31.8||1976-06-04||2||40°13'N / 104°49'W||1.50 Miles||200 Yards||0||0||25K||0||Weld|
|31.8||1981-06-03||2||39°44'N / 105°02'W||39°44'N / 105°01'W||0||0||2.5M||0||Denver|
|35.1||1988-06-15||2||39°44'N / 104°56'W||0.50 Mile||400 Yards||0||0||2.5M||0||Denver|
|35.1||1988-06-15||3||39°44'N / 104°56'W||2.50 Miles||200 Yards||0||7||25.0M||0||Denver|
|35.1||2008-05-22||3||40°13'N / 104°45'W||40°33'N / 104°57'W||24.00 Miles||1760 Yards||1||78||147.0M||0K||Weld|
|Brief Description: EVENT NARRATIVE: A powerful tornado swept north-northwestward across Weld County and into Larimer County, carving a path of destruction, nearly 39 miles in length. The tornado, up to one-mile wide at times, initially touched down northeast of Platteville and finally lifted 6 miles west-northwest of Wellington. A tornado assessment in the aftermath of the tornado revealed extensive areas of damage. On the enhanced Fujita Scale there were pockets of EF3 damage, mainly near the Missile Silo Park Campground, and to businesses and home in eastern Windsor. There was one fatality, and 78 injuries. One man was killed when he tried to escape the trailer park in his motor home. Preliminary estimates from FEMA indicated 850 homes were damaged, and nearly 300 homes were significantly damaged or destroyed. Privately insured damages totaled $147 million, and the Poudre Valley Rural Electric Associated reported $1 million of damage to electric transmission lines. EPISODE NARRATIVE: A powerful tornado swept north-northwestward across Weld County, carving a path of destruction, nearly 39 miles in length. The tornado, up to one-mile wide at times, initially touched down northeast of Platteville and finally lifted 6 miles west-northwest of Wellington. A tornado assessment in the aftermath of the tornado revealed extensive areas of damage. On the enhanced Fujita Scale there were pockets of EF3 damage, mainly near the Missile Silo Park Campground, and to businesses and home in eastern Windsor. Farmers also reported extensive damage to crops and irrigation equipment. There was one fatality, and 78 injuries ranging from broken bones to minor cuts and lacerations. One man was killed when he tried to escape a trailer park in his motor home. Tractor trailers were flipped along U.S. Highway 85, and over 200 power poles were snapped or blown down. Approximately 60,000 people were left without electricity. The tornado overturned 15 railroad cars and destroyed a lumber car on the Great Western Railway of Colorado. The tornado also flattened Windsor's main feedlot and destroyed a dairy barn. Most of the four-hundred cows were killed in the tornado or destroyed later. In addition to the damaging winds, the thunderstorm also produced hail up to the size of baseballs. Another tornado rated an EF1, from a separate severe thunderstorm, briefly touched down near Dacono and destroyed 5 buildings. The tornado overturned a five-wheel trailer and injured the man who was sitting inside. Preliminary estimates from FEMA indicated 850 homes were damaged, and nearly 300 homes were significantly damaged or destroyed. The Poudre Valley Rural Electric Association reported $1 million of damage to electric transmission lines. Privately insured damages totaled $147 million, making it the state's 4th costliest disaster.|
|35.5||1976-05-30||2||39°48'N / 104°53'W||39°50'N / 104°47'W||5.40 Miles||67 Yards||0||0||250K||0||Adams|
|36.4||1957-05-30||2||40°28'N / 104°56'W||40°28'N / 104°53'W||1.90 Miles||33 Yards||0||0||3K||0||Larimer|
|36.9||1957-05-30||2||40°30'N / 104°56'W||40°28'N / 104°54'W||1.30 Miles||33 Yards||0||1||3K||0||Weld|
|37.1||1986-06-08||2||39°43'N / 104°54'W||1.00 Mile||50 Yards||0||6||2.5M||0||Denver|
|37.3||1957-05-30||2||40°28'N / 104°53'W||40°27'N / 104°52'W||0||0||3K||0||Weld|
|37.6||1976-06-04||2||40°35'N / 105°05'W||0.50 Mile||300 Yards||0||0||0K||0||Larimer|
|38.1||1987-07-02||2||39°53'N / 104°44'W||1.00 Mile||250 Yards||0||0||3K||0||Adams|
|39.1||1986-06-08||2||39°43'N / 104°51'W||39°43'N / 104°51'W||0.10 Mile||50 Yards||0||0||2.5M||0||Arapahoe|
|40.4||1958-06-08||2||40°04'N / 104°42'W||40°06'N / 104°34'W||7.10 Miles||33 Yards||0||0||3K||0||Weld|
|40.5||1957-05-30||2||40°27'N / 104°52'W||40°33'N / 104°49'W||7.20 Miles||33 Yards||0||0||3K||0||Weld|
|41.0||1975-05-18||3||39°48'N / 104°44'W||39°51'N / 104°41'W||4.10 Miles||440 Yards||0||0||0K||0||Adams|
|41.1||1984-05-18||2||40°07'N / 104°40'W||40°12'N / 104°35'W||5.00 Miles||50 Yards||0||0||25K||0||Weld|
|45.0||1982-06-25||2||40°23'N / 104°38'W||1.00 Mile||200 Yards||0||0||0K||0||Weld|
|45.9||1986-06-08||2||39°50'N / 104°36'W||2.00 Miles||100 Yards||0||0||0K||0||Adams|
|46.2||1984-05-18||2||40°07'N / 104°35'W||40°10'N / 104°28'W||5.00 Miles||50 Yards||0||0||0K||0||Weld|
|46.9||1978-05-17||2||39°38'N / 104°45'W||0.50 Mile||33 Yards||0||0||250K||0||Adams|
|47.2||1987-06-20||2||39°46'N / 104°37'W||1.00 Mile||30 Yards||0||0||0K||0||Adams|
|47.2||1984-05-18||2||40°11'N / 104°34'W||40°14'N / 104°28'W||5.00 Miles||50 Yards||0||0||3K||0||Weld|
|47.7||1955-07-10||2||40°31'N / 104°42'W||40°35'N / 104°44'W||4.30 Miles||33 Yards||0||0||3K||0||Weld|
|47.9||1985-07-19||2||39°32'N / 104°52'W||0.50 Mile||40 Yards||0||0||250K||0||Douglas|
|48.4||1952-05-15||3||40°20'N / 104°34'W||40°15'N / 104°28'W||7.40 Miles||150 Yards||0||5||25K||0||Weld|
|48.8||1982-06-12||3||39°49'N / 104°32'W||39°53'N / 104°32'W||3.00 Miles||400 Yards||0||0||3K||0||Adams|
* 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.