August 15
- 1787 – The largest known tornado outbreak of at the time, the Four-State Tornado Swarm produced tornadoes across Connecticut, Rhode Island, Massachusetts, and New Hampshire. Two people were killed, and ten were injured, by a tornado in Wethersfield, Connecticut, where the "black column whirled with amazing velocity and a most tremendous roar." One tornado moved across parts of three states from near Killingly, Connecticut to Gloucester, Massachusetts, cutting across Rhode Island.
- 2008 – A significant tornado outbreak hit southern Poland. An F3 (T6) tornado killed two people in Rusinowice and Kalina and injured 40 others. About 800 structures were damaged. An strong F3 (T7) tornado caused major damage in Sieroniowice, destroying thick brick walls and injuring 15 people.