May 31 edit
1889: The Johnstown Flood, caused by days of heavy rains which led to the failure of the South Fork Dam, killed more than 2,000 people in Johnstown, Pennsylvania.
1953: Tropical Storm Alice moved over the western tip of Cuba.
1985: More than 40 tornadoes were spawned around the eastern Great Lakes in the 1985 United States-Canadian tornado outbreak, including the only F5 ever recorded in that area.
2013: The widest tornado ever recorded struck the area near El Reno, Oklahoma, killing 8 people, including renowned tornado researcher Tim Samaras.