Alton School District Natural Disasters and Weather Extremes
Hot Rankings
The chance of earthquake damage in Alton School District is lower than New Hampshire average and is lower than the national average. The risk of tornado damage in Alton School District is about the same as New Hampshire average and is lower than the national average.
Earthquake Index, #77
| Alton School District | 0.70 |
| New Hampshire | 1.01 |
| 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
| Alton School District | 0.0000 |
| New Hampshire | 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, #97
| Alton School District | 67.86 |
| New Hampshire | 65.04 |
| 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 2,282 other weather extremes events within 50 miles of Alton School District 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: | 1 | Cold: | 11 | Dense Fog: | 0 | Drought: | 10 |
| Dust Storm: | 0 | Flood: | 231 | Hail: | 573 | Heat: | 3 | Heavy Snow: | 134 |
| High Surf: | 0 | Hurricane: | 0 | Ice Storm: | 8 | Landslide: | 0 | Strong Wind: | 98 |
| Thunderstorm Winds: | 864 | Tropical Storm: | 0 | Wildfire: | 0 | Winter Storm: | 26 | Winter Weather: | 4 |
| Other: | 319 | ||||||||
Volcanos Nearby
No volcano is found in or near Alton School District.
Historical Earthquake Events
A total of 5 historical earthquake events that had recorded magnitudes of 3.5 or above found in or near Alton School District.
| Distance (miles) | Date | Magnitude | Depth (km) | Latitude | Longitude |
| 18.5 | 1940-12-24 | 5.6 | N/A | 43.75 | -71.25 |
| 19.9 | 1940-12-20 | 5.6 | N/A | 43.7 | -71.5 |
| 19.1 | 1982-01-19 | 4.7 | 7 | 43.51 | -71.62 |
| 19.8 | 1963-12-04 | 3.7 | 33 | 43.6 | -71.6 |
| 42.3 | 1979-07-28 | 3.5 | 11 | 43.29 | -70.44 |
Historical Tornado Events
A total of 25 historical tornado events that had recorded magnitude of 2 or above found in or near Alton School District.
| Distance (miles) | Date | Magnitude | Start Lat/Log | End Lat/Log | Length | Width | Fatalities | Injuries | Property Damage | Crop Damage | Affected County |
| 5.2 | 2008-07-24 | 2 | 43°27'N / 71°10'W | 43°34'N / 71°07'W | 8.00 Miles | 880 Yards | 0 | 0 | 0K | 0K | Strafford |
| Brief Description: EVENT NARRATIVE: An E-F1 tornado, moving north northeast out of Belknap County, entered Strafford County approximately 2.2 miles north northwest of New Durham. The storm skipped along for more than 8 miles before exiting into Carroll County. The intensity of the tornado varied between F0 and F2, and numerous trees were blown down along the path of the storm. EPISODE NARRATIVE: On July 24th a closed 500 mb low was digging over NY/PA and waves of surface low pressure were riding north along the associated surface front to the west of the forecast area. A strong 50kt low level jet was also riding northward ahead of the front. This resulted in extremely high helicity values across southern and central New Hampshire. A surface dew point boundary was in place across south central New Hampshire with readings in the lower 70s to the east of this boundary and in the mid 60s to the west. Sunshine began breaking out to the east of this boundary by mid morning and convection began developing by late morning. Storms grew rapidly and quickly began rotating. A tornado rated as strong as F2 cut a 50 mile path through 5 counties in southeast New Hampshire resulting in 1 fatality and damage to over 100 structures some of which were completely destroyed. | |||||||||||
| 8.1 | 2008-07-24 | 2 | 43°17'N / 71°15'W | 43°27'N / 71°10'W | 12.00 Miles | 880 Yards | 0 | 0 | 0K | 0K | Belknap |
| Brief Description: EVENT NARRATIVE: An E-F2 tornado moving north northeast out of Rockingham County entered Belknap County about 2 miles southwest of South Barnstead near Province Road. The storm travaled almost 12 miles before crossing into Strafford County resulting in E-F0 to E-F2 damage. There were numerous houses and buildings that were damaged or destroyed by the tornado or by falling trees. In addition, there were thousands of downed trees and numerous power lines down along the path of the storm. EPISODE NARRATIVE: On July 24th a closed 500 mb low was digging over NY/PA and waves of surface low pressure were riding north along the associated surface front to the west of the forecast area. A strong 50kt low level jet was also riding northward ahead of the front. This resulted in extremely high helicity values across southern and central New Hampshire. A surface dew point boundary was in place across south central New Hampshire with readings in the lower 70s to the east of this boundary and in the mid 60s to the west. Sunshine began breaking out to the east of this boundary by mid morning and convection began developing by late morning. Storms grew rapidly and quickly began rotating. A tornado rated as strong as F2 cut a 50 mile path through 5 counties in southeast New Hampshire resulting in 1 fatality and damage to over 100 structures some of which were completely destroyed. | |||||||||||
| 8.4 | 1963-07-18 | 2 | 43°36'N / 71°12'W | 0.10 Mile | 17 Yards | 0 | 0 | 25K | 0 | Carroll | |
| 9.3 | 1981-06-22 | 2 | 43°26'N / 71°10'W | 43°23'N / 71°00'W | 8.70 Miles | 40 Yards | 0 | 0 | 2.5M | 0 | Strafford |
| 10.6 | 1999-07-06 | 2 | 43°20'N / 71°11'W | 43°20'N / 71°11'W | 2.00 Miles | 250 Yards | 0 | 0 | 0 | 0 | Strafford |
| Brief Description: Severe thunderstorm winds caused damage statewide as downed trees blocked roads and caused power outages. The winds also damaged several buildings. In Sanbornton, a 60 foot pine tree fell on a car killing the driver. An F2 tornado touched down in Pittsfield, moved through Barnstead, and then into Strafford before lifting off the ground, snapping and uprooting hundreds of trees, and damaging several homes. In Lebanon, a 50 x 70 ft section of the City Hall's copper roof was peeled back by the wind. In Hanover, a portion of a roof at Dartmouth College was blown off by the wind. In Claremont, the wind ripped the roof off a bandstand. The wind left 80,000 customers without electrical service statewide. Numerous trees were reported down in towns throughout the state and numerous roads throughout the state were closed. The heavy rain that accompanied the thunderstorms caused some of the small rivers and streams to rise rapidly. In Lincoln, two brothers swimming in the East Branch of the Pemigewasset River were swept away by the rapidly rising water; one of the boys was bounced down the river for about a quarter mile before grabbing hold of a rock in the water. A 14-tear-old boy was injured in Piermont when lightning struck nearby and entered the cabin through electrical wires. Lightning also caused fires in several homes and buildings. | |||||||||||
| 10.7 | 1999-07-06 | 2 | 43°20'N / 71°18'W | 43°20'N / 71°18'W | 4.50 Miles | 300 Yards | 0 | 0 | 0 | 0 | Belknap |
| Brief Description: Severe thunderstorm winds caused damage statewide as downed trees blocked roads and caused power outages. The winds also damaged several buildings. In Sanbornton, a 60 foot pine tree fell on a car killing the driver. An F2 tornado touched down in Pittsfield, moved through Barnstead, and then into Strafford before lifting off the ground, snapping and uprooting hundreds of trees, and damaging several homes. In Lebanon, a 50 x 70 ft section of the City Hall's copper roof was peeled back by the wind. In Hanover, a portion of a roof at Dartmouth College was blown off by the wind. In Claremont, the wind ripped the roof off a bandstand. The wind left 80,000 customers without electrical service statewide. Numerous trees were reported down in towns throughout the state and numerous roads throughout the state were closed. The heavy rain that accompanied the thunderstorms caused some of the small rivers and streams to rise rapidly. In Lincoln, two brothers swimming in the East Branch of the Pemigewasset River were swept away by the rapidly rising water; one of the boys was bounced down the river for about a quarter mile before grabbing hold of a rock in the water. A 14-tear-old boy was injured in Piermont when lightning struck nearby and entered the cabin through electrical wires. Lightning also caused fires in several homes and buildings. | |||||||||||
| 10.7 | 1972-07-03 | 2 | 43°25'N / 71°26'W | 1.00 Mile | 40 Yards | 0 | 7 | 25K | 0 | Belknap | |
| 16.0 | 2008-07-24 | 2 | 43°13'N / 71°16'W | 43°17'N / 71°15'W | 5.00 Miles | 880 Yards | 0 | 0 | 0K | 0K | Merrimack |
| Brief Description: EVENT NARRATIVE: An E-F2 tornado moving north northeast out of Rockingham County crossed into Merrimack County near Route 202 and continued north northeast a little over 5 miles before entering Belknap County. Homes and buildins in the tornadoes path sustained damage along the path which was up to a half mile wide. EPISODE NARRATIVE: On July 24th a closed 500 mb low was digging over NY/PA and waves of surface low pressure were riding north along the associated surface front to the west of the forecast area. A strong 50kt low level jet was also riding northward ahead of the front. This resulted in extremely high helicity values across southern and central New Hampshire. A surface dew point boundary was in place across south central New Hampshire with readings in the lower 70s to the east of this boundary and in the mid 60s to the west. Sunshine began breaking out to the east of this boundary by mid morning and convection began developing by late morning. Storms grew rapidly and quickly began rotating. A tornado rated as strong as F2 cut a 50 mile path through 5 counties in southeast New Hampshire resulting in 1 fatality and damage to over 100 structures some of which were completely destroyed. | |||||||||||
| 18.3 | 2008-07-24 | 2 | 43°34'N / 71°07'W | 43°51'N / 70°59'W | 20.00 Miles | 880 Yards | 0 | 0 | 0K | 0K | Carroll |
| Brief Description: EVENT NARRATIVE: An E-F2 tornado moving out of Strafford County crossed into Carroll 2.9 miles east of South Wolfboro and continued to skip north northeast for almost 20 miles through the town of Freedom. F0 to F2 damage occurred along the path of the storm and many thousands of trees were blown down. Cars, homes and other structures were also damaged. EPISODE NARRATIVE: On July 24th a closed 500 mb low was digging over NY/PA and waves of surface low pressure were riding north along the associated surface front to the west of the forecast area. A strong 50kt low level jet was also riding northward ahead of the front. This resulted in extremely high helicity values across southern and central New Hampshire. A surface dew point boundary was in place across south central New Hampshire with readings in the lower 70s to the east of this boundary and in the mid 60s to the west. Sunshine began breaking out to the east of this boundary by mid morning and convection began developing by late morning. Storms grew rapidly and quickly began rotating. A tornado rated as strong as F2 cut a 50 mile path through 5 counties in southeast New Hampshire resulting in 1 fatality and damage to over 100 structures some of which were completely destroyed. | |||||||||||
| 20.7 | 2008-07-24 | 2 | 43°09'N / 71°18'W | 43°13'N / 71°16'W | 5.00 Miles | 880 Yards | 1 | 2 | 0K | 0K | Rockingham |
| Brief Description: EVENT NARRATIVE: An E-F2 tornado touched down about 5 miles southwest of Northwood Narrows and moved north northeast for a little over 5 miles before crossing into Merrimack County. Numerous trees were downed and many homes were damaged or destroyed. A woman was killed when the house she was in collapsed. EPISODE NARRATIVE: On July 24th a closed 500 mb low was digging over NY/PA and waves of surface low pressure were riding north along the associated surface front to the west of the forecast area. A strong 50kt low level jet was also riding northward ahead of the front. This resulted in extremely high helicity values across southern and central New Hampshire. A surface dew point boundary was in place across south central New Hampshire with readings in the lower 70s to the east of this boundary and in the mid 60s to the west. Sunshine began breaking out to the east of this boundary by mid morning and convection began developing by late morning. Storms grew rapidly and quickly began rotating. A tornado rated as strong as F2 cut a 50 mile path through 5 counties in southeast New Hampshire resulting in 1 fatality and damage to over 100 structures some of which were completely destroyed. | |||||||||||
| 21.2 | 1963-05-14 | 2 | 43°18'N / 71°00'W | 43°16'N / 70°50'W | 8.20 Miles | 50 Yards | 0 | 0 | 25K | 0 | Strafford |
| 23.1 | 1966-10-10 | 2 | 43°26'N / 70°47'W | 0.20 Mile | 50 Yards | 0 | 0 | 25K | 0 | York | |
| 25.2 | 1963-05-14 | 2 | 43°16'N / 70°50'W | 43°16'N / 70°50'W | 0.50 Mile | 50 Yards | 0 | 0 | 3K | 0 | York |
| 31.0 | 1976-05-03 | 2 | 43°08'N / 70°51'W | 1.00 Mile | 33 Yards | 0 | 0 | 250K | 0 | Strafford | |
| 34.4 | 1957-06-19 | 2 | 43°06'N / 70°48'W | 0.20 Mile | 77 Yards | 0 | 1 | 25K | 0 | Rockingham | |
| 35.1 | 1961-07-02 | 2 | 43°06'N / 71°42'W | 2.00 Miles | 17 Yards | 0 | 0 | 3K | 0 | Hillsborough | |
| 36.0 | 1973-05-11 | 2 | 43°34'N / 71°57'W | 0.50 Mile | 150 Yards | 0 | 0 | 0K | 0 | Grafton | |
| 38.1 | 1953-06-09 | 3 | 42°58'N / 70°58'W | 1.50 Miles | 100 Yards | 0 | 5 | 25K | 0 | Rockingham | |
| 39.3 | 1963-06-09 | 2 | 43°00'N / 71°30'W | 42°52'N / 71°24'W | 10.00 Miles | 77 Yards | 0 | 0 | 250K | 0 | Hillsborough |
| 43.1 | 1951-08-21 | 2 | 42°50'N / 71°08'W | 42°54'N / 71°04'W | 4.90 Miles | 67 Yards | 0 | 0 | 3K | 0 | Rockingham |
| 43.7 | 2006-05-21 | 2 | 42°55'N / 70°51'W | 42°55'N / 70°51'W | 0.10 Mile | 20 Yards | 0 | 2 | 3K | 0 | Rockingham |
| Brief Description: A small, but rather intense, tornado touched down on Interstate 95 about two miles south of the Hampton Toll Booths in the town of Hampton Falls. While several funnel clouds were observed over southeastern New Hampshire that Sunday evening, the actual tornado touched down just as one of the funnel clouds approached I-95. The tornado then lifted off the ground about 100 yards after crossing I-95. The most significant damage was to a truck parked along the side of the highway. The trucked was lifted off the ground briefly by the tornado, thrown about 10 feet, landed on the passenger side, and then rolled 1 1/4 times ending up on its roof. Two men were in the truck at the time and were taken to a nearby hospital for treatment. After interviews with the occupants and eyewitness reports which indicated that the vehicle was lifted into the air, the tornado intensity was classified as F2 on the Fujita scale. These reports were consistent with the ground-based assessment. | |||||||||||
| 47.1 | 1961-07-02 | 2 | 42°50'N / 71°16'W | 42°46'N / 71°12'W | 5.10 Miles | 400 Yards | 0 | 1 | 250K | 0 | Rockingham |
| 47.3 | 1998-05-31 | 2 | 43°02'N / 71°57'W | 43°02'N / 71°57'W | 0.50 Mile | 85 Yards | 0 | 0 | 30K | 0 | Hillsborough |
| Brief Description: A short-duration minimal F2 tornado moved along a half-mile long track which averaged 85 yards wide in Antrim in northwest Hillsborough County. A National Weather Service survey team investigated the damaging effects of this tornado and spoke with many eyewitnesses. One resident recalled seeing the NWS' Tornado Warning (which specifically mentioned Antrim) scroll on Cable TV a few minutes before the tornado struck. The tornado began at Nahor Hill and travelled north-northeast about a half mile before ending up just past the Great Brook Elementary School. Along the middle of its path, a wooded stretch sustained severe tree damage. Most of the trees were either uprooted or snapped in half...and they fell in different directions. A small boat was flipped over and a camper-trailer was turned around and flipped over. A single family home had some shingles torn off. An apartment complex resident said he saw the metal garbage dumpster rise a short distance while a dark gray-black cloud went by. At the elementary school, a wall was damaged. Only minor damage and no injuries occurred as a result of this tornado, but had the track been only a few hundred yards to the east, it could have caused significant damage to the center of the small town of Antrim. | |||||||||||
| 47.9 | 1997-07-03 | 2 | 42°57'N / 71°51'W | 42°57'N / 71°51'W | 2.00 Miles | 250 Yards | 0 | 0 | 250K | 0 | Hillsborough |
| Brief Description: Very severe thunderstorms moved through Cheshire and Hillsborough Counties, producing two tornadoes, microbursts, damaging thunderstorm winds, and large hail. It appears that a microburst hit Hinsdale and both a microburst and weak tornado affected the town of Swanzey, just south of Keene, in Cheshire County. A horse barn was destroyed and an ice arena damaged at the Cheshire Fairgrounds. Pieces of aluminum were wrapped around street lamps and two-by-fours were driven into the metal sides and roof of the ice arena. One person was slightly injured by flying glass fragments when her car windows were blown in. Many trees were uprooted or blown down. Damage was estimated at approximately $500,000 at the Fairgrounds. There was evidence of both straight-line wind damage and some rotation associated with this storm. In Hillsborough County, a tornado touched down in the western portion of the town of Greenfield just to the west of Otter Lake. It then moved to the northeast, damaging a sawmill, destroying a recycling facility, and damaging some buildings at a campground. Wood and aluminum buildings were torn apart or blown over. Many large trees were broken off near their bases and hundreds more had their tops broken off. There were no injuries reported. Trees were reported blown down in Marlborough and a microburst may have occurred in nearby Dublin, where numerous trees and tree limbs were blown down along the shore of the Howe Reservoir. All of the aforementioned damage was along a path cut by the same thunderstorm complex. However, trees also were reported blown down in the towns of Walpole and Marlow in northern Cheshire County from a separate cluster of thunderstorms. About 1,700 electric customers in the Monadnock Region lost power during the storms. Most of the outages occurred in the towns of Marlborough, Marlow, Richmond, Swanzey, and Winchester. Another 100 lost power in Walpole. Statewide, about 10,000 electric customers lost power. | |||||||||||
| 48.6 | 1956-11-21 | 2 | 42°48'N / 71°00'W | 0.80 Mile | 17 Yards | 0 | 0 | 25K | 0 | Essex | |
* 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.