Pennsylvania recorded 967 tornadoes from 1950 through 2024, an average of 13 a year, in NOAA’s Storm Prediction Center database. They killed 85 people. The busiest year was 1998, with 59.
Tornadoes per 1,000 square miles since 1950: none under 10 10 to 25 25 to 50 50 to 75 75 to 100 over 100. Tap a county for its history.
Tornadoes by year
The rise since the 1990s is mostly better detection of weak tornadoes, not a jump in strong ones.
Tornado season in Pennsylvania
July is the peak, with 211 tornadoes since 1950 (22% of the total).
How strong
| Rating | Estimated 3-second gust | Tornadoes |
|---|---|---|
| F0 / EF0 | Light damage: 65 to 85 mph (EF scale) | 275 |
| F1 / EF1 | Moderate: 86 to 110 mph | 481 |
| F2 / EF2 | Considerable: 111 to 135 mph | 172 |
| F3 / EF3 | Severe: 136 to 165 mph | 28 |
| F4 / EF4 | Devastating: 166 to 200 mph | 8 |
| F5 / EF5 | Incredible: over 200 mph | 1 |
| EF-U | Unknown: no damage to rate (mostly since 2016) | 2 |
Pennsylvania has had 1 F5 or EF5 tornado, the top of the scale.
The deadliest tornadoes in Pennsylvania
| Date | Rating | Deaths in Pennsylvania | Counties |
|---|---|---|---|
| May 31, 1985 | F4 | 16 | Crawford County, Forest County, Mercer County, Venango County |
| May 31, 1985 | F4 | 12 | Erie County |
| May 31, 1985 | F3 | 9 | Beaver County, Butler County |
| May 31, 1985 | F5 | 8 | Mercer County |
| May 31, 1985 | F4 | 7 | Forest County, Venango County |
| May 31, 1985 | F3 | 6 | Lycoming County, Northumberland County, Union County |
| May 31, 1985 | F4 | 4 | Elk County, McKean County, Warren County |
| July 27, 1994 | F3 | 3 | Montgomery County |
| August 3, 1963 | F3 | 2 | Allegheny County |
| May 31, 1985 | F3 | 2 | Crawford County |
Counties with the most tornadoes
| County | Tornadoes since 1950 | Per 1,000 sq mi | Strongest |
|---|---|---|---|
| Westmoreland County | 47 | 45 | F4 |
| Crawford County | 39 | 38 | F4 |
| Lancaster County | 37 | 38 | F3 |
| York County | 35 | 38 | F3 |
| Chester County | 31 | 41 | F3 |
| Allegheny County | 29 | 39 | F4 |
| Lycoming County | 29 | 23 | F3 |
| Bucks County | 28 | 45 | EF3 |
| Berks County | 26 | 30 | F3 |
| Butler County | 26 | 33 | F3 |
| Beaver County | 24 | 54 | F3 |
| Mercer County | 24 | 35 | F5 |
| Erie County | 22 | 27 | F4 |
| Cambria County | 22 | 32 | F2 |
| Dauphin County | 21 | 38 | F2 |
Big counties collect more tornadoes simply because they are big. By area, the most tornado-dense counties are Philadelphia County (77 per 1,000 sq mi), Beaver County (54 per 1,000 sq mi), Lebanon County (53 per 1,000 sq mi), Lehigh County (46 per 1,000 sq mi), Westmoreland County (45 per 1,000 sq mi).
Every county in Pennsylvania
Staying safe
When a tornado warning is issued, act at once. Go to a basement, storm shelter or safe room. With none, use a small windowless room on the lowest floor, as far from outside walls as you can, and cover your head and neck. Mobile homes and cars are not safe places to ride out a tornado: leave early for a sturdy building or shelter. Read the full tornado safety guide and the National Weather Service advice linked below.
Sources
- NOAA Storm Prediction Center: Severe Weather Database, tornadoes 1950 to 2024 (public domain)
- NOAA Storm Prediction Center: The Enhanced Fujita Scale (EF scale)
- National Weather Service: Tornado safety
Sources last checked 1 November 2026.
Frequently asked questions
How many tornadoes does Pennsylvania get a year?
About 13 on average from 1950 to 2024; recent years run higher because weak tornadoes are better detected.
When is tornado season in Pennsylvania?
July has had the most. Spring and early summer bring most of them.
What was the deadliest tornado in Pennsylvania?
May 31, 1985: 16 deaths in Pennsylvania.