The counties that experience the most tornadoes in the U.S.

As things heat up this summer, towns across the U.S. may see the sky above darken, and clouds shift into ominous looking spirals. In counties across the Midwest, tornado season is upon us. Recently, WeatherDB, a weather data site that’s part of Graphiq, discovered which counties in the U.S. suffered the most damage from tornadoes in the last twenty years, but which counties experience the most tornadoes?

WeatherDB found out which 10 U.S. counties experienced the most tornadoes between 1951 and 2015. Data was collected from NOAA‘s Severe Weather Data Inventory. Counties are ranked by their Tornado Frequency, which is measured in tornadoes per year per 1,000 square miles. It is the average number of tornadoes that would hit the county per year, if the county was exactly 1,000 square miles. The area of the county was taken into account so larger counties were not weighted higher than smaller counties. Damage, death and injury numbers were gathered for each county. The total damage for each tornado was adjusted for inflation to today’s dollars, and ties were broken using total adjusted damages.

To many, the South is synonymous with hurricanes. However, tornadoes are another natural hazard that southern states like Louisiana, Alabama and Florida experience annually. In fact, six separate counties in the South made it on this list. Texas is also home to multiple tornado-damaged counties. Tornadoes damage many areas in the U.S. we may not expect.

Tornado Frequency: 2.16 per year
Most Tornadoes in a Year: 8 (in 1971)
Total Adjusted Damages: $314.8 million
Total Deaths: 0
Total Injuries: 33

Note: Tornado frequency is per 1,000 sq. mi.

Tornado Frequency: 2.17 per year
Most Tornadoes in a Year: 10 (in 1990)
Total Adjusted Damages: $58.3 million
Total Deaths: 1
Total Injuries: 30

Note: Tornado frequency is per 1,000 sq. mi.

Tornado Frequency: 2.17 per year
Most Tornadoes in a Year: 15 (in 1980)
Total Adjusted Damages: $1.07 billion
Total Deaths: 5
Total Injuries: 205

Note: Tornado frequency is per 1,000 sq. mi.

Tornado Frequency: 2.2 per year
Most Tornadoes in a Year: 9 (in 1960)
Total Adjusted Damages: $3.05 billion
Total Deaths: 42
Total Injuries: 669

Note: Tornado frequency is per 1,000 sq. mi.

Tornado Frequency: 2.27 per year
Most Tornadoes in a Year: 4 (in 1975)
Total Adjusted Damages: $84.1 million
Total Deaths: 2
Total Injuries: 41

Note: Tornado frequency is per 1,000 sq. mi.

Tornado Frequency: 2.29 per year
Most Tornadoes in a Year: 17 (in 1988)
Total Adjusted Damages: $81.4 million
Total Deaths: 0
Total Injuries: 43

Tornado Frequency: 2.45 per year
Most Tornadoes in a Year: 7 (in 1974)
Total Adjusted Damages: $1.21 billion
Total Deaths: 16
Total Injuries: 529

Note: Tornado frequency is per 1,000 sq. mi.

Tornado Frequency: 2.7 per year
Most Tornadoes in a Year: 3 (in 1991)
Total Adjusted Damages: $133.5 million
Total Deaths: 4
Total Injuries: 71

Note: Tornado frequency is per 1,000 sq. mi.

Tornado Frequency: 4.74 per year
Most Tornadoes in a Year: 7 (in 1983)
Total Adjusted Damages: $89.4 million
Total Deaths: 9
Total Injuries: 243

Note: Tornado frequency is per 1,000 sq. mi.

Tornado Frequency: 7.3 per year
Most Tornadoes in a Year: 13 (in 1992)
Total Adjusted Damages: $308.3 million
Total Deaths: 11
Total Injuries: 310

Note: Tornado frequency is per 1,000 sq. mi.