The U.S. experiences more tornadoes than any other country in the world by more than a 10:1 margin. On average, the U.S. records 1,253 tornadoes annually, according to the National Oceanic and Atmospheric Administration (NOAA). For context, the U.S. total is nearly 13-times greater than that of second-place Canada, experiencing an average of 100 tornadoes each year. While tornadoes can occur at any time of the year and in any state, the bulk of twisters occur in the most at-risk areas in the South and the Plains — including Tornado Alley — located between Central Texas and South Dakota where highest levels of tornadic activity are recorded anywhere in the world. Looking at annual tornado activity by region, NOAA's National Centers for Environmental Information (NCEI) compiled the 20-year annual average for every state, based on data from 1991 to 2010. From NOAA's findings, in the slideshow above, discover which 10 states experience the most tornadoes annually based on a 20-year average.  See also:

• Flood, windstorm checklist for commercial and industrial buildings
• Insurers prepare for impending disasters
• Everything you need in your emergency 'go' bag