This is a list of tornadoes by their official and unofficial width. The average width of a tornado according to the National Weather Service is 50 yards (46 m). The official widest tornado in history is the 2013 El Reno tornado, which had a confirmed width of 2.6 miles (4.2 km), with the World Meteorological Organization believing the width could have been up to 1 mile (1.6 km) wider.