Counties with the most tornadoes in Pennsylvania

(STACKER) — It’s been a busy year for tornadoes in the U.S. According to the National Oceanic and Atmospheric Administration, as many as 1,155 twisters have touched down across the country since the start of the year, above the average for this time of year.

A single day can drive up tornado counts. March 31, 2023, accounted for 163 tornadoes across the Midwest and South. Tornado activity usually peaks in the spring and early summer, and the pace of tornadoes usually slows around late summer. A smaller-scale second tornado season emerges in the fall, mostly in the Gulf Coast states.

Stacker used data from NOAA’s National Centers for Environmental Information to find the counties in Pennsylvania that have experienced the most tornadoes since 2000. While data is available going back to 1950, tornado tracking by the National Weather Service became more robust and accurate in the 1990s. Since counties can vary in size, they are ranked by the number of tornadoes per 100 square miles. Counties that experienced less than five tornadoes are not included.

The counties that encounter the most tornadoes aren’t all in the infamous Tornado Alley. When adjusted for county area, the top 10 counties that experienced the most tornadoes since 2000 are from nine different states, all in the Southeast with the exception of Cleveland County, Oklahoma.

Research has shown that Tornado Alley is shifting due to warming temperatures fueled by climate change. In the future, the Southeast could become the region that receives the bulk of the country’s tornadoes. It’s a concerning trend as the South is more populated than the Great Plains and has a higher concentration of mobile homes than other parts of the country, making the storms potentially deadlier and costlier.

As of August 2023, 75 people have died from tornadoes this year, and over 60% of those deaths occurred in mobile homes.

The best way to stay protected during tornadoes is to have multiple ways of receiving storm updates including social media, radio, television, and sirens, and to immediately seek shelter in a basement or interior room without windows when a tornado watch escalates to a warning.

Read on to see which counties experience the most tornadoes in Pennsylvania.

#39. Somerset County

– Tornadoes since 2000: 5 (0.47 per 100 square miles)
– #1,986 nationally
– Tornadoes this year, as of May 31: 0

#38. Bedford County

– Tornadoes since 2000: 5 (0.49 per 100 square miles)
– #1,979 nationally
– Tornadoes this year, as of May 31: 0

#37. Potter County

– Tornadoes since 2000: 6 (0.55 per 100 square miles)
– #1,959 nationally
– Tornadoes this year, as of May 31: 0

#36. Erie County

– Tornadoes since 2000: 5 (0.63 per 100 square miles)
– #1,935 nationally
– Tornadoes this year, as of May 31: 0

#35. Luzerne County

– Tornadoes since 2000: 6 (0.67 per 100 square miles)
– #1,925 nationally
– Tornadoes this year, as of May 31: 0

#34. Venango County

– Tornadoes since 2000: 5 (0.74 per 100 square miles)
– #1,902 nationally
– Tornadoes this year, as of May 31: 0

#33. Berks County

– Tornadoes since 2000: 7 (0.82 per 100 square miles)
– #1,868 nationally
– Tornadoes this year, as of May 31: 1

#32. Susquehanna County

– Tornadoes since 2000: 7 (0.85 per 100 square miles)
– #1,850 nationally
– Tornadoes this year, as of May 31: 0

#31. Bradford County

– Tornadoes since 2000: 10 (0.87 per 100 square miles)
– #1,843 nationally
– Tornadoes this year, as of May 31: 0

#30. Lycoming County

– Tornadoes since 2000: 11 (0.90 per 100 square miles)
– #1,828 nationally
– Tornadoes this year, as of May 31: 0

#29. Franklin County

– Tornadoes since 2000: 7 (0.91 per 100 square miles)
– #1,822 nationally
– Tornadoes this year, as of May 31: 0

#28. Indiana County

– Tornadoes since 2000: 8 (0.97 per 100 square miles)
– #1,795 nationally
– Tornadoes this year, as of May 31: 0

#27. Montgomery County

– Tornadoes since 2000: 5 (1.04 per 100 square miles)
– #1,762 nationally
– Tornadoes this year, as of May 31: 0

#26. Washington County

– Tornadoes since 2000: 9 (1.05 per 100 square miles)
– #1,756 nationally
– Tornadoes this year, as of May 31: 0

#25. Jefferson County

– Tornadoes since 2000: 7 (1.07 per 100 square miles)
– #1,737 nationally
– Tornadoes this year, as of May 31: 0

#24. Northumberland County

– Tornadoes since 2000: 5 (1.09 per 100 square miles)
– #1,729 nationally
– Tornadoes this year, as of May 31: 0

#23. Allegheny County

– Tornadoes since 2000: 8 (1.10 per 100 square miles)
– #1,725 nationally
– Tornadoes this year, as of May 31: 0

#22. Wayne County

– Tornadoes since 2000: 8 (1.10 per 100 square miles)
– #1,717 nationally
– Tornadoes this year, as of May 31: 0

#21. Sullivan County

– Tornadoes since 2000: 5 (1.11 per 100 square miles)
– #1,709 nationally
– Tornadoes this year, as of May 31: 0

#20. Fulton County

– Tornadoes since 2000: 5 (1.14 per 100 square miles)
– #1,681 nationally
– Tornadoes this year, as of May 31: 0

#19. Elk County

– Tornadoes since 2000: 10 (1.21 per 100 square miles)
– #1,641 nationally
– Tornadoes this year, as of May 31: 0

#18. York County

– Tornadoes since 2000: 11 (1.22 per 100 square miles)
– #1,633 nationally
– Tornadoes this year, as of May 31: 0

#17. Warren County

– Tornadoes since 2000: 11 (1.24 per 100 square miles)
– #1,599 nationally
– Tornadoes this year, as of May 31: 0

#16. Westmoreland County

– Tornadoes since 2000: 13 (1.27 per 100 square miles)
– #1,575 nationally
– Tornadoes this year, as of May 31: 0

#15. Lackawanna County

– Tornadoes since 2000: 6 (1.31 per 100 square miles)
– #1,550 nationally
– Tornadoes this year, as of May 31: 0

#14. Forest County

– Tornadoes since 2000: 6 (1.40 per 100 square miles)
– #1,478 nationally
– Tornadoes this year, as of May 31: 0

#13. Crawford County

– Tornadoes since 2000: 15 (1.48 per 100 square miles)
– #1,427 nationally
– Tornadoes this year, as of May 31: 0

#12. Lancaster County

– Tornadoes since 2000: 14 (1.48 per 100 square miles)
– #1,426 nationally
– Tornadoes this year, as of May 31: 0

#11. Clarion County

– Tornadoes since 2000: 9 (1.50 per 100 square miles)
– #1,416 nationally
– Tornadoes this year, as of May 31: 0

#10. Butler County

– Tornadoes since 2000: 12 (1.52 per 100 square miles)
– #1,407 nationally
– Tornadoes this year, as of May 31: 0

#9. Union County

– Tornadoes since 2000: 5 (1.58 per 100 square miles)
– #1,367 nationally
– Tornadoes this year, as of May 31: 0

#8. Beaver County

– Tornadoes since 2000: 7 (1.61 per 100 square miles)
– #1,345 nationally
– Tornadoes this year, as of May 31: 0

#7. Mercer County

– Tornadoes since 2000: 11 (1.64 per 100 square miles)
– #1,323 nationally
– Tornadoes this year, as of May 31: 0

#6. Cumberland County

– Tornadoes since 2000: 9 (1.65 per 100 square miles)
– #1,312 nationally
– Tornadoes this year, as of May 31: 0

#5. Dauphin County

– Tornadoes since 2000: 9 (1.71 per 100 square miles)
– #1,266 nationally
– Tornadoes this year, as of May 31: 0

#4. Lehigh County

– Tornadoes since 2000: 6 (1.74 per 100 square miles)
– #1,254 nationally
– Tornadoes this year, as of May 31: 0

#3. Juniata County

– Tornadoes since 2000: 7 (1.79 per 100 square miles)
– #1,215 nationally
– Tornadoes this year, as of May 31: 0

#2. Bucks County

– Tornadoes since 2000: 12 (1.99 per 100 square miles)
– #1,070 nationally
– Tornadoes this year, as of May 31: 1

#1. Lebanon County

– Tornadoes since 2000: 8 (2.21 per 100 square miles)
– #922 nationally
– Tornadoes this year, as of May 31: 0