On August 20, 1970, an F3 tornado hit the Canadian city of Sudbury, Ontario.
Considered unusual because tornadoes of this strength rarely occur in Northern Ontario, the tornado touched down in the suburban community of Lively. The tornado tracked quickly eastward into the city, hitting the neighbourhoods of Copper Cliff and Robinson over the next ten minutes. Another tornado associated with the same storm also hit the community of Field, approximately 50 kilometres east of Sudbury, less than an hour later.
Six people died and 200 were injured in the tornado, which caused an estimated $17 million in damage, including to an Inco smelter in Copper Cliff. It is currently tied for the status of the eighth deadliest tornado in Canadian history.
| Rank | Name (location) | Date | Deaths | |
|---|---|---|---|---|
| 1 | Regina Cyclone | June 30, 1912 | ≥28 | |
| 2 | Edmonton Tornado | July 31, 1987 | 27 | |
| 3 | Windsor–Tecumseh, Ontario tornado | June 17, 1946 | 17 | |
| 4 | Pine Lake Tornado | July 14, 2000 | 12 | |
| =5 | Salaberry-de-Valleyfield, Quebec Windsor, Ontario tornado |
August 16, 1888 April 3, 1974 |
9 9 |
|
| 7 | Barrie, Ontario tornado | May 31, 1985 | 8 | |
| =8 | Sudbury, Ontario tornado Sainte-Rose, Quebec tornado |
August 20, 1970 June 8, 1953 |
6 6 |
|
| =10 | Bouctouche, New Brunswick tornado Portage la Prairie, Manitoba tornado |
August 6, 1879 June 22, 1922 |
5 5 |
|
|
Sources: Environment Canada (PDF) |
||||