Many of us may remember the jaw-dropping images of the May 22, 2011, tornado that tore through Joplin, Mo., killing 158 people and leaving an incredible 14-mile path of destruction. But that system was only one of the record-breaking tornado events this year. Data compiled by meteorologist Jeffrey Masters shows that when deaths, damage and financial losses are considered, 2011 can be called the worst U.S. tornado year on record.

Masters, who runs the Weather Underground, a Web site that provides local forecasts, analyzes severe weather and turns raw storm data from the National Weather Service into captivating maps and data visualizations, has posted a compilation of record and near-record tornado events for 2011. Some notable stats from his post are below. A blow-by-blow description of the year’s major tornadoes, as well as a list of the deadliest tornadoes in U.S. history, can be found on NOAA’s 2011 tornado review page.

  • Six top-end EF-5 tornadoes hit the U.S. in 2011, tying this year with 1974 for the greatest number.
  • 2011 ranks third behind 1974 and 1965 for the greatest number of strong to violent EF-3, EF-4 and EF-5 tornadoes.
  • Three of the five largest outbreaks on record hit in a six-week period in April and May.
  • April 2011 had the most tornadoes of any month in U.S. history: 753. The previous record was 542 in May 2003.
  • On April 27, 199 confirmed tornadoes touched down, the largest one-day total on record, beating the 148 that occurred in 24 hours on April 3 - 4, 1974.
  • The April 25 - 28, 2011, super outbreak of 343 tornadoes was the largest and most expensive outbreak in U.S. history, according to Masters, causing $10.2 billion in damage.
  • The May 22, 2011, tornado in Joplin killed 158 people and injured 1,150, making it the deadliest U.S. tornado since 1947, and the seventh deadliest in history. The $3 billion in insured damages makes it the most expensive tornado in world history.

The overall tornado death toll of 552 in 2011 ties 1936 as the second deadliest year in U.S. history. Masters notes on his site that during the 1930s, the tornado death rate per million people was 60 to 70 times greater than in the year 2000, “implying that this year's tornadoes may have killed tens of thousands of people if we did not have our modern tornado warning system.” The dubious record for the most fatal storm is held by the Tri-State Tornado (Missouri, Illinois, Indiana) of March 18, 1925, which killed 695 people.

Photo of Joplin, Mo., courtesy of Xpda on Flickr