Franklin County Natural Disasters and Weather Extremes
The chance of earthquake damage in Franklin County is about the same as Pennsylvania average and is much lower than the national average. The risk of tornado damage in Franklin County is lower than Pennsylvania average and is lower than the national average.
Earthquake Index, #29
| Franklin County | 0.04 |
| Pennsylvania | 0.17 |
| 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
| Franklin County | 0.0000 |
| Pennsylvania | 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, #40
| Franklin County | 90.80 |
| Pennsylvania | 109.77 |
| 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 14,141 other weather extremes events within 50 miles of Franklin 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: | 8 | Cold: | 77 | Dense Fog: | 42 | Drought: | 79 |
| Dust Storm: | 0 | Flood: | 2,078 | Hail: | 2,270 | Heat: | 150 | Heavy Snow: | 208 |
| High Surf: | 0 | Hurricane: | 3 | Ice Storm: | 45 | Landslide: | 0 | Strong Wind: | 276 |
| Thunderstorm Winds: | 7,561 | Tropical Storm: | 8 | Wildfire: | 19 | Winter Storm: | 186 | Winter Weather: | 147 |
| Other: | 984 | ||||||||
Volcanos Nearby
No volcano is found in or near Franklin County.
Historical Earthquake Events
No historical earthquake events that had recorded magnitudes of 3.5 or above found in or near Franklin County.
No historical earthquake events found in or near Franklin County.
Historical Tornado Events
A total of 28 historical tornado events that had recorded magnitude of 2 or above found in or near Franklin County.
| Distance (miles) | Date | Magnitude | Start Lat/Log | End Lat/Log | Length | Width | Fatalities | Injuries | Property Damage | Crop Damage | Affected County |
| 13.9 | 1961-04-16 | 3 | 40°03'N / 77°31'W | 0 | 0 | 250K | 0 | Cumberland | |||
| 25.1 | 1976-03-21 | 2 | 39°56'N / 77°15'W | 1.00 Mile | 50 Yards | 0 | 0 | 25K | 0 | Adams | |
| 30.0 | 1983-05-22 | 3 | 39°42'N / 77°15'W | 39°42'N / 77°14'W | 1.00 Mile | 37 Yards | 0 | 0 | 25K | 0 | Frederick |
| 30.9 | 1983-05-22 | 3 | 39°42'N / 77°14'W | 39°43'N / 77°12'W | 1.00 Mile | 37 Yards | 0 | 0 | 25K | 0 | Carroll |
| 32.6 | 1989-06-20 | 2 | 40°22'N / 77°30'W | 2.00 Miles | 23 Yards | 0 | 1 | 25K | 0 | Perry | |
| 33.5 | 1954-04-25 | 2 | 39°50'N / 77°14'W | 39°48'N / 76°59'W | 13.30 Miles | 500 Yards | 0 | 0 | 25K | 0 | Adams |
| 36.8 | 1980-06-07 | 2 | 40°01'N / 77°04'W | 40°02'N / 77°01'W | 2.30 Miles | 800 Yards | 0 | 0 | 2.5M | 0 | Adams |
| 37.0 | 2004-09-17 | 2 | 39°24'N / 77°33'W | 39°24'N / 77°39'W | 3.00 Miles | 200 Yards | 0 | 0 | 5K | 0 | Frederick |
| Brief Description: An F2 tornado touched down in far northwest Frederick County, on the northwest edge of Catoctin Mountain Park. A thickly forested stand of hardwood trees was snapped off above the bases. | |||||||||||
| 37.3 | 1955-08-19 | 2 | 40°24'N / 77°23'W | 0 | 0 | 25K | 0 | Chester | |||
| 37.5 | 1980-06-07 | 3 | 39°56'N / 77°01'W | 1.50 Miles | 400 Yards | 0 | 0 | 250K | 0 | Adams | |
| 38.7 | 1996-07-19 | 2 | 39°23'N / 77°42'W | 39°21'N / 77°42'W | 2.00 Miles | 125 Yards | 0 | 0 | 400K | 75K | Washington |
| Brief Description: A moderate tornado (F2) tracked between two mountain ridges in extreme southern Washington Co, knocking down hundreds of trees, including several onto homes which caused substantial damage. At least one barn was completely destroyed in Yarrowsburg. The storm attained maximum strength just south of town (where the trees, including numerous hardwoods, were flattened). The tornado weakened considerably before dissipating along the eastern ridge. Structural and vehicle damage, though not as prevalent as the tree damage, included the following: Portions of roofs from two barns were blown off; minor residential damage, including shattered windows, unhinged shingles, and torn off trim/gutters. Some gravestones were overturned by the winds, and several power lines were knocked down. Several vehicles and vehicle windows were damaged. | |||||||||||
| 39.0 | 1978-08-28 | 2 | 39°48'N / 77°02'W | 39°45'N / 77°00'W | 3.30 Miles | 20 Yards | 0 | 0 | 3K | 0 | Adams |
| 39.9 | 1980-06-07 | 2 | 40°02'N / 77°01'W | 40°02'N / 76°57'W | 3.30 Miles | 33 Yards | 0 | 0 | 2.5M | 0 | York |
| 41.1 | 1978-08-28 | 2 | 39°45'N / 77°00'W | 39°43'N / 76°59'W | 1.90 Miles | 33 Yards | 0 | 0 | 3K | 0 | York |
| 41.5 | 1978-07-31 | 2 | 39°24'N / 77°21'W | 1.50 Miles | 100 Yards | 0 | 0 | 25K | 0 | Frederick | |
| 41.5 | 2004-09-17 | 2 | 39°22'N / 78°02'W | 39°23'N / 78°02'W | 2.00 Miles | 100 Yards | 0 | 6 | 25K | 0 | Berkeley |
| Brief Description: A tornado touched down in Darkesville in southern Berkeley County. The F2 tornado produced extensive structural damage to homes and businesses in the area. The storm traveled north and toppled tractor trailers and vehicles on Interstate-81. At least 6 people were injured from the automobile accidents. | |||||||||||
| 42.1 | 2001-09-24 | 2 | 39°44'N / 76°59'W | 39°48'N / 76°56'W | 5.00 Miles | 200 Yards | 0 | 0 | 900K | 0 | York |
| Brief Description: A tornado touched down near Grand Valley Road at 17:33 EST about 5 miles South of Hanover PA. The tornado proceded northward, through Parkville then lifting to the north of Blooming Grove at 17:40 EST. The path of the tornado was about 5 miles in length but not always on the ground while the width varied from 50 to 200 yards. The top wind speeds were estimated at 110 to 120 mph. There were no injuries or deaths. Significant damage included 8 homes with roofs torn off, brick and structural damage to several additional homes, 50 to 75 trees knocked down, 38 cars damaged at a car dealership, significant roof and water damage to a middle school and administration building, and significant structural damage to a store complex northwest of Blooming Grove. | |||||||||||
| 43.0 | 1992-10-09 | 2 | 40°07'N / 76°57'W | 2.00 Miles | 100 Yards | 0 | 0 | 2.5M | 0 | York | |
| 44.0 | 1989-11-16 | 2 | 39°15'N / 77°47'W | 39°20'N / 77°48'W | 9.00 Miles | 50 Yards | 0 | 3 | 250K | 0 | Jefferson |
| 44.3 | 1967-09-21 | 2 | 40°25'N / 77°11'W | 0.10 Mile | 30 Yards | 0 | 0 | 250K | 0 | Perry | |
| 44.3 | 1990-06-08 | 2 | 39°49'N / 76°54'W | 1.00 Mile | 60 Yards | 0 | 1 | 250K | 0 | York | |
| 45.2 | 1979-05-23 | 2 | 39°35'N / 77°00'W | 2.00 Miles | 150 Yards | 0 | 0 | 2.5M | 0 | Carroll | |
| 46.5 | 1952-04-05 | 3 | 39°48'N / 76°59'W | 39°57'N / 76°43'W | 17.50 Miles | 33 Yards | 0 | 4 | 2.5M | 0 | York |
| 47.7 | 1985-07-31 | 2 | 40°10'N / 76°54'W | 40°09'N / 76°51'W | 3.00 Miles | 20 Yards | 0 | 2 | 250K | 0 | Lancaster |
| 48.4 | 1952-07-23 | 2 | 40°37'N / 77°34'W | 0 | 4 | 25K | 0 | Mifflin | |||
| 48.8 | 1978-08-28 | 2 | 39°43'N / 76°59'W | 39°34'N / 76°47'W | 14.80 Miles | 33 Yards | 0 | 0 | 0K | 0 | Frederick |
| 49.0 | 1989-11-20 | 2 | 40°37'N / 77°49'W | 40°39'N / 77°47'W | 3.50 Miles | 1230 Yards | 0 | 0 | 25K | 0 | Huntingdon |
| 49.1 | 1961-07-13 | 2 | 39°19'N / 78°12'W | 0 | 1 | 3K | 0 | Frederick | |||
* 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.