Groton-Dunstable School District Natural Disasters and Weather Extremes
Hot Rankings
The chance of earthquake damage in Groton-Dunstable School District is about the same as Massachusetts average and is lower than the national average. The risk of tornado damage in Groton-Dunstable School District is higher than Massachusetts average and is lower than the national average.
Earthquake Index, #121
| Groton-Dunstable School District | 0.70 |
| Massachusetts | 0.70 |
| 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
| Groton-Dunstable School District | 0.0000 |
| Massachusetts | 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, #104
| Groton-Dunstable School District | 116.28 |
| Massachusetts | 87.60 |
| 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 3,171 other weather extremes events within 50 miles of Groton-Dunstable 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: | 9 |
| Dust Storm: | 0 | Flood: | 307 | Hail: | 663 | Heat: | 3 | Heavy Snow: | 145 |
| High Surf: | 0 | Hurricane: | 0 | Ice Storm: | 8 | Landslide: | 0 | Strong Wind: | 103 |
| Thunderstorm Winds: | 1,408 | Tropical Storm: | 0 | Wildfire: | 0 | Winter Storm: | 26 | Winter Weather: | 4 |
| Other: | 483 | ||||||||
Volcanos Nearby
No volcano is found in or near Groton-Dunstable School District.
Historical Earthquake Events
A total of 1 historical earthquake event that had a recorded magnitude of 3.5 or above found in or near Groton-Dunstable School District.
| Distance (miles) | Date | Magnitude | Depth (km) | Latitude | Longitude |
| 38.7 | 1963-10-16 | 4.5 | 20 | 42.5 | -70.8 |
Historical Tornado Events
A total of 40 historical tornado events that had recorded magnitude of 2 or above found in or near Groton-Dunstable School District.
| Distance (miles) | Date | Magnitude | Start Lat/Log | End Lat/Log | Length | Width | Fatalities | Injuries | Property Damage | Crop Damage | Affected County |
| 5.0 | 1970-10-03 | 3 | 42°33'N / 71°32'W | 42°34'N / 71°31'W | 1 | 0 | 250K | 0 | Middlesex | ||
| 8.4 | 1972-07-21 | 2 | 42°41'N / 71°25'W | 42°35'N / 71°20'W | 7.60 Miles | 37 Yards | 0 | 4 | 2.5M | 0 | Middlesex |
| 11.6 | 1965-08-28 | 2 | 42°42'N / 71°20'W | 2.00 Miles | 33 Yards | 0 | 0 | 250K | 0 | Middlesex | |
| 12.6 | 1957-07-05 | 2 | 42°32'N / 71°45'W | 0.50 Mile | 20 Yards | 0 | 0 | 3K | 0 | Worcester | |
| 15.2 | 1958-07-11 | 2 | 42°30'N / 71°18'W | 1.50 Miles | 17 Yards | 0 | 0 | 250K | 0 | Middlesex | |
| 16.2 | 1963-05-20 | 2 | 42°24'N / 71°36'W | 0.30 Mile | 50 Yards | 0 | 0 | 3K | 0 | Worcester | |
| 16.5 | 1974-09-29 | 3 | 42°36'N / 71°14'W | 42°37'N / 71°12'W | 0 | 1 | 250K | 0 | Middlesex | ||
| 17.8 | 1956-11-21 | 2 | 42°24'N / 71°42'W | 0.10 Mile | 17 Yards | 0 | 0 | 2.5M | 0 | Worcester | |
| 17.8 | 1963-05-20 | 2 | 42°24'N / 71°42'W | 1.50 Miles | 33 Yards | 0 | 0 | 25K | 0 | Worcester | |
| 19.2 | 1968-07-17 | 2 | 42°50'N / 71°48'W | 0.10 Mile | 17 Yards | 0 | 0 | 25K | 0 | Hillsborough | |
| 19.5 | 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 |
| 20.4 | 1970-10-03 | 3 | 42°20'N / 72°10'W | 42°33'N / 71°32'W | 35.40 Miles | 60 Yards | 0 | 0 | 250K | 0 | Worcester |
| 21.5 | 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 |
| 22.8 | 1981-06-22 | 3 | 42°30'N / 72°02'W | 42°33'N / 71°54'W | 7.10 Miles | 167 Yards | 0 | 3 | 25K | 0 | Worcester |
| 22.9 | 1953-06-09 | 4 | 42°28'N / 72°10'W | 42°18'N / 71°31'W | 34.90 Miles | 900 Yards | 90 | 1228 | 250.0M | 0 | Worcester |
| 25.9 | 1951-08-21 | 2 | 42°42'N / 71°08'W | 42°46'N / 70°58'W | 9.30 Miles | 100 Yards | 0 | 0 | 3K | 0 | Essex |
| 26.3 | 1966-08-31 | 2 | 42°18'N / 71°48'W | 1.00 Mile | 67 Yards | 0 | 0 | 0K | 0 | Worcester | |
| 27.1 | 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. | |||||||||||
| 27.7 | 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 |
| 28.0 | 1972-08-09 | 2 | 42°33'N / 72°08'W | 42°41'N / 72°03'W | 9.70 Miles | 10 Yards | 0 | 1 | 25K | 0 | Worcester |
| 28.3 | 1958-08-25 | 2 | 42°32'N / 71°00'W | 1.00 Mile | 50 Yards | 0 | 0 | 3K | 0 | Middlesex | |
| 29.8 | 1956-11-21 | 2 | 42°48'N / 71°00'W | 0.80 Mile | 17 Yards | 0 | 0 | 25K | 0 | Essex | |
| 33.1 | 1979-08-10 | 2 | 42°19'N / 72°08'W | 42°19'N / 71°56'W | 9.70 Miles | 30 Yards | 2 | 2 | 2.5M | 0 | Worcester |
| 33.4 | 1961-07-02 | 2 | 43°06'N / 71°42'W | 2.00 Miles | 17 Yards | 0 | 0 | 3K | 0 | Hillsborough | |
| 34.6 | 1953-06-09 | 3 | 42°10'N / 71°46'W | 42°06'N / 71°29'W | 14.90 Miles | 667 Yards | 0 | 1 | 2.5M | 0 | Worcester |
| 34.7 | 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. | |||||||||||
| 36.3 | 1963-08-13 | 2 | 42°50'N / 72°12'W | 2.00 Miles | 17 Yards | 0 | 0 | 250K | 0 | Cheshire | |
| 37.2 | 1956-11-21 | 2 | 42°10'N / 71°10'W | 0.10 Mile | 17 Yards | 0 | 0 | 3K | 0 | Norfolk | |
| 37.2 | 1953-06-09 | 3 | 42°58'N / 70°58'W | 1.50 Miles | 100 Yards | 0 | 5 | 25K | 0 | Rockingham | |
| 38.2 | 1963-05-20 | 2 | 42°18'N / 72°12'W | 42°21'N / 72°08'W | 3.80 Miles | 17 Yards | 0 | 0 | 25K | 0 | Worcester |
| 38.3 | 1969-06-06 | 2 | 42°54'N / 72°12'W | 1.50 Miles | 150 Yards | 0 | 0 | 3K | 0 | Cheshire | |
| 39.4 | 1953-06-09 | 3 | 42°06'N / 71°29'W | 42°03'N / 71°14'W | 13.10 Miles | 667 Yards | 0 | 15 | 2.5M | 0 | Norfolk |
| 40.2 | 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. | |||||||||||
| 40.4 | 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. | |||||||||||
| 41.2 | 1962-10-12 | 2 | 42°08'N / 71°58'W | 42°05'N / 71°54'W | 4.10 Miles | 133 Yards | 0 | 0 | 25K | 0 | Worcester |
| 43.3 | 1953-06-09 | 3 | 42°03'N / 71°14'W | 42°03'N / 71°12'W | 0 | 1 | 2.5M | 0 | Bristol | ||
| 44.0 | 2006-07-11 | 2 | 42°33'N / 72°24'W | 42°33'N / 72°24'W | 2.90 Miles | 200 Yards | 0 | 0 | 200K | 0 | Franklin |
| Brief Description: Brief F2 Touchdown in Wendell Hot and humid air in place over southern New England set the stage for severe thunderstorms throughout the Bay State during the afternoon and early evening. Although storm damage was reported from the Connecticut Valley region to the Worcester Hills and Merrimack Valley, damage was especially severe in eastern Franklin County as well as Boston's North Shore. Early in the afternoon, one cluster of thunderstorms formed in Franklin County and rapidly became severe, causing considerable damage in Montague and especially Wendell. A damage survey conducted by the National Weather Service concluded the damage in Wendell was caused by a combination of straight-line wind damage and a tornado, which was rated as a strong F2 on the Fujita Scale with winds estimated near 155 mph. Damage began around 230 pm EDT, about 200 yards west of Montague Road. Wind damage extended from Montague Road about 1.5 miles east to Wicket Pond in the Wendell State Forest. Large oak, maple, and pine trees were uprooted and snapped in this area. Some oaks over two feet in diameter were snapped about 10 to 15 feet from the ground. Damage from this microburst extended along a path of one and a half miles in length, and anywhere from 50 to 300 yards in width. Wind speeds were estimated near 90 mph. Tornado damage first appeared on the northeast corner of Wicket Pond. An eyewitness reported seeing a six foot wave form on the pond. On the west side of the pond, many trees were snapped 15 to 20 feet above the ground, with debris left in a chaotic pattern. The next area of damage was on Wicket Pond Road, which is where the most severe damage occurred. Trees as large as 3 feet in diameter were uprooted. Bark was stripped off trees and a house had part of its roof torn off. The tornado tracked to the east along Wicket Pond Road, passing over Depot Road which is in Wendell Center. Part of a roof was torn off an old barn and many trees were uprooted. After crossing Depot Road, the tornado continued to track to the east, passing north of Morse Village Road. A construction storage trailer was completely destroyed and its roof was wrapped around a tree. Trees were also uprooted or snapped in this area. Damage came to an end about one half mile east of New Salem Road. The path length of the tornado was approximately 3 miles. Its average width was 200 yards, varying from 100 to 300 yards. A little more than one hour later, another cluster of severe thunderstorms brought significant damage to Cape Ann, in particular Marblehead Neck and the adjacent coastal waters. Initially, the storms produced hail as large as 3 inches in diameter - just larger than baseball size - which are considered to be the second largest hailstones reported in Massachusetts. A National Weather Service storm survey concluded that multiple wet microbursts, or sudden outflow of damaging straight-line winds combined with torrential rainfall, impacted the area around Marblehead Neck between 357 pm and 430 pm EDT. The survey noted that westerly winds gusting as high as 90 mph occurred in an area centered from Marblehead Harbor across Corinthian Lane and Barker Lane, and then out to sea. The land damage path was short, primarily because the land is only about 700 feet wide in that area. The main damage path was about 150 feet wide. It consisted of tree damage and minor structural damage, although substantial damage was noted to sailing vessels and at least one car. Damage was more sporadic near Manley Street, about 600 feet farther north, and also to the south and southwest on Foster Street, Harbor Avenue, and Ocean Avenue. Interviews with eyewitnesses provide more detail as to how the storms affected the area. Between 340 pm and 345 pm EDT, winds shifted to the northeast and produced sea spray at the mouth of Marblehead Harbor. This was the result of earlier thunderstorms passing north of the area. Then, from 357 pm to 405 pm EDT, a white tempest developed over Marblehead Harbor on the neck side of the harbor, estimated by the Corinthian Yacht Club chair to be about 300 yards upstream from the dock. This curtain of water and high winds advanced toward the yacht club, lifting 30-foot vessels approximately 20 feet in the air and catapulting them end over end toward the dock. An anemometer on the dock was viewed to have reached 95 mph before it blew off its mast. Damage was less severe, but still significant, from the Connecticut Valley to the Worcester Hills and Merrimack Valley. There were many reports of downed trees, large branches, and hail up to the size of quarters from the Springfield area to Grafton, Westborough, and Framingham as well as farther northeast into Hardwick, Wilmington, and Boxford. Torrential rainfall caused significant urban flooding, especially in Springfield, Oxford, Wakefield, and Beverly. In Salem, two cars on Pope Street were submerged by up to 3 feet of water when about 2 inches of rain fell in 20 minutes. Other cars were flooded in Salem and Lynn due to other roads being flooded, including a stretch of Route 129. Lightning struck Athol Memorial Hospital, causing minor damage to the facility. | |||||||||||
| 45.1 | 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. | |||||||||||
| 49.3 | 1976-05-03 | 2 | 43°08'N / 70°51'W | 1.00 Mile | 33 Yards | 0 | 0 | 250K | 0 | Strafford | |
| 49.6 | 1957-06-19 | 2 | 43°06'N / 70°48'W | 0.20 Mile | 77 Yards | 0 | 1 | 25K | 0 | Rockingham | |
* 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.