Most tornadoes in 24 hours

From 25–28 April 2011, a massive tornado outbreak ravaged northeast, southern and Midwest regions of the USA. The peak activity occurred between 1AM CDT 27 April and 1AM CDT 28 April, with a total of 207 distinct tornadoes forming across the 24-hour period, according to the World Meteorological Organization.

The official National Oceanic and Atmospheric Administration Storm Data for 27 April 2011 list tornado numbers:

F0: 62

F1: 77

F2: 33

F3: 20

F4: 11

F5: 4

In addition, the month of April 2011 also set an record high for the number of US tornadoes for a given month at 760.