Moore, Oklahoma, tornado May 20, 2013 The most recent EF5 tornado in U.S. occurred on May 20, 2013, when a devastating twister barreled through Moore, Oklahoma, killing 24 and injuring hundreds more.

David McNeese/Getty Images for CNN An aerial view of the destruction caused by the massive tornado that struck areas south of Oklahoma City on Monday, May 20, shows the magnitude of damage left in ...

Researches found little evidence that tornadoes were getting weaker. Instead, it appears that a subjective tornado grading system is to blame.

Homes are being built better than they were a few decades ago to account for the Oklahoma severe weather season.

A severe weather threat brings a hail and low tornado risk to parts of Oklahoma as storms are expected Wednesday afternoon ...

Sunday's tornado warning in Oklahoma lined up with the generally agreed start of tornado season. Here's what to know about the season and its peak.

Tornadoes are among the strongest and deadliest types of weather, capable of destroying entire neighborhoods in minutes. However, the most powerful tornadoes, classified as EF5, make up less than 1% ...