List of United States tornadoes in April 2011
This is a list of all tornadoes that were confirmed by local offices of the National Weather Service in the United States in April 2011. It was, by a wide margin, the most active tornado month in United States history, with 781 tornadoes being confirmed from April 4 to April 30.
Source: Wikipedia — List of United States tornadoes in April 2011 (CC BY-SA 4.0)