Perry County Natural Disasters and Weather Extremes
The chance of earthquake damage in Perry County is about the same as Pennsylvania average and is much lower than the national average. The risk of tornado damage in Perry County is lower than Pennsylvania average and is lower than the national average.
Earthquake Index, #27
| Perry 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
| Perry 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, #35
| Perry County | 95.36 |
| 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 13,448 other weather extremes events within 50 miles of Perry 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: | 5 | Cold: | 79 | Dense Fog: | 39 | Drought: | 77 |
| Dust Storm: | 0 | Flood: | 1,981 | Hail: | 2,099 | Heat: | 141 | Heavy Snow: | 189 |
| High Surf: | 0 | Hurricane: | 3 | Ice Storm: | 36 | Landslide: | 1 | Strong Wind: | 258 |
| Thunderstorm Winds: | 7,140 | Tropical Storm: | 5 | Wildfire: | 28 | Winter Storm: | 167 | Winter Weather: | 155 |
| Other: | 1,045 | ||||||||
Volcanos Nearby
No volcano is found in or near Perry County.
Historical Earthquake Events
A total of 1 historical earthquake event that had a recorded magnitude of 3.5 or above found in or near Perry County.
| Distance (miles) | Date | Magnitude | Depth (km) | Latitude | Longitude |
| 42.6 | 1964-05-12 | 4.5 | 33 | 40.2 | -76.5 |
Historical Tornado Events
A total of 41 historical tornado events that had recorded magnitude of 2 or above found in or near Perry County.
| Distance (miles) | Date | Magnitude | Start Lat/Log | End Lat/Log | Length | Width | Fatalities | Injuries | Property Damage | Crop Damage | Affected County |
| 4.6 | 1967-09-21 | 2 | 40°25'N / 77°11'W | 0.10 Mile | 30 Yards | 0 | 0 | 250K | 0 | Perry | |
| 6.2 | 1955-08-19 | 2 | 40°24'N / 77°23'W | 0 | 0 | 25K | 0 | Chester | |||
| 12.5 | 1989-06-20 | 2 | 40°22'N / 77°30'W | 2.00 Miles | 23 Yards | 0 | 1 | 25K | 0 | Perry | |
| 21.8 | 1952-07-23 | 2 | 40°37'N / 77°34'W | 0 | 4 | 25K | 0 | Mifflin | |||
| 22.7 | 1980-04-09 | 2 | 40°44'N / 77°19'W | 40°43'N / 77°17'W | 0 | 0 | 250K | 0 | Snyder | ||
| 25.0 | 1977-04-05 | 2 | 40°15'N / 76°50'W | 2.00 Miles | 67 Yards | 0 | 1 | 2.5M | 0 | Dauphin | |
| 25.6 | 1992-10-09 | 2 | 40°07'N / 76°57'W | 2.00 Miles | 100 Yards | 0 | 0 | 2.5M | 0 | York | |
| 26.4 | 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 |
| 27.4 | 1961-04-16 | 3 | 40°03'N / 77°31'W | 0 | 0 | 250K | 0 | Cumberland | |||
| 27.8 | 1970-03-26 | 2 | 40°16'N / 76°46'W | 2.50 Miles | 50 Yards | 0 | 0 | 250K | 0 | Dauphin | |
| 28.3 | 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 |
| 29.3 | 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 |
| 30.5 | 1950-07-05 | 2 | 40°36'N / 76°45'W | 0 | 0 | 3K | 0 | Dauphin | |||
| 32.1 | 1976-03-21 | 2 | 39°56'N / 77°15'W | 1.00 Mile | 50 Yards | 0 | 0 | 25K | 0 | Adams | |
| 32.4 | 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 |
| 32.4 | 1967-10-18 | 2 | 40°13'N / 76°45'W | 40°19'N / 76°36'W | 10.20 Miles | 30 Yards | 0 | 11 | 250K | 0 | Dauphin |
| 34.2 | 1991-09-18 | 2 | 40°40'N / 77°49'W | 40°42'N / 77°47'W | 4.00 Miles | 330 Yards | 0 | 3 | 250K | 0 | Huntingdon |
| 34.7 | 1980-06-07 | 3 | 39°56'N / 77°01'W | 1.50 Miles | 400 Yards | 0 | 0 | 250K | 0 | Adams | |
| 36.6 | 1957-11-19 | 2 | 40°18'N / 76°35'W | 2.00 Miles | 13 Yards | 0 | 0 | 25K | 0 | Lebanon | |
| 36.8 | 2004-07-14 | 3 | 40°17'N / 76°35'W | 40°17'N / 76°35'W | 7.50 Miles | 500 Yards | 0 | 0 | 18.0M | 0 | Lebanon |
| Brief Description: Thunderstorms spawned a strong F3 tornado in southern Lebanon County during the afternoon of July 14. The tornado first touched down in far western Lebanon County at 3:05 pm EDT, about 1 mile west of the town of Campbelltown. The tornado traveled east, and struck a housing development about one quarter mile south of Route 322. A total of 32 homes were destroyed, with another 37 homes sustaining significant damage. An additional 50 homes and 9 farm buildings in the area were damaged by downburst winds associated with the thunderstorm which spawned the tornado. The tornado continued along a path to the east for seven and one half miles. The tornado crossed Route 322 west of Mount Pleasant, and continued east, mainly across fields, until it lifted up about 2 miles northwest of the town of Cornwall at 3:15 pm EDT. The width of the tornado was one quarter mile. Although the tornadic damage was confined to the path described, additional damage occurred outside this path, again associated with downburst winds from the parent thunderstorm. Winds were estimated between 175 and 200 MPH, making this a strong F3 tornado on the Fujita scale. The tornado injured 24 persons, one critically. There were no deaths. The American Red Cross opened a mass care center, where over 50 people required assistance with sheltering. Between 25,000 and 30,000 customers lost power in Lebanon and Berks Counties as a result of the storms. | |||||||||||
| 37.6 | 1969-07-27 | 2 | 40°04'N / 76°42'W | 0.30 Mile | 100 Yards | 0 | 0 | 250K | 0 | York | |
| 37.8 | 1953-09-12 | 2 | 40°40'N / 76°41'W | 40°39'N / 76°35'W | 4.70 Miles | 50 Yards | 0 | 0 | 3K | 0 | Northumberland |
| 38.3 | 1970-07-02 | 2 | 40°09'N / 76°37'W | 1.00 Mile | 1760 Yards | 0 | 0 | 25K | 0 | Lancaster | |
| 38.3 | 1991-05-06 | 2 | 40°05'N / 76°40'W | 1.00 Mile | 100 Yards | 0 | 3 | 250K | 0 | Lancaster | |
| 39.5 | 1978-08-28 | 2 | 40°53'N / 76°52'W | 40°51'N / 76°48'W | 3.30 Miles | 50 Yards | 0 | 1 | 25K | 0 | Snyder |
| 39.8 | 1963-03-27 | 2 | 40°00'N / 76°51'W | 40°03'N / 76°32'W | 17.00 Miles | 20 Yards | 0 | 0 | 25K | 0 | York |
| 40.6 | 1978-08-28 | 2 | 40°51'N / 76°48'W | 40°52'N / 76°46'W | 0 | 0 | 25K | 0 | Northumberland | ||
| 41.0 | 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 |
| 41.9 | 1975-06-05 | 2 | 40°45'N / 77°55'W | 0 | 0 | 250K | 0 | Centre | |||
| 42.3 | 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 |
| 42.4 | 1956-06-13 | 2 | 39°57'N / 76°43'W | 0 | 2 | 25K | 0 | York | |||
| 44.5 | 1990-06-08 | 2 | 39°49'N / 76°54'W | 1.00 Mile | 60 Yards | 0 | 1 | 250K | 0 | York | |
| 45.0 | 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 |
| 45.3 | 1989-06-15 | 2 | 39°58'N / 76°40'W | 40°02'N / 76°30'W | 9.00 Miles | 100 Yards | 0 | 3 | 250K | 0 | York |
| 46.4 | 1961-07-29 | 2 | 39°58'N / 76°40'W | 39°59'N / 76°30'W | 8.80 Miles | 500 Yards | 0 | 0 | 2.5M | 0 | York |
| 46.4 | 1992-07-17 | 2 | 40°24'N / 76°23'W | 1.00 Mile | 30 Yards | 0 | 0 | 250K | 0 | Lebanon | |
| 46.5 | 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. | |||||||||||
| 47.7 | 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 |
| 48.1 | 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 |
| 48.2 | 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 |
| 49.1 | 1989-06-15 | 2 | 40°02'N / 76°30'W | 40°02'N / 76°26'W | 4.00 Miles | 100 Yards | 0 | 3 | 250K | 0 | Lancaster |
* 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.