Originally Posted by
eigenvector
The probability of seeing the northern lights with the naked eye anywhere in southern Ontario in summer is vanishingly small. For a good chance of seeing it you want to visit somewhere at least as far north as Winnipeg/Edmonton/Prince George and in the winter when there's many hours of darkness. Yellowknife is ideal if you really want to be guaranteed a glimpse during a relatively short visit.
Thanks
Winnipeg, Manitoba (closer to Minnesota, US)
Churchill, Manitoba
Edmonton, Alberta
Prince George, BC
Prince George, BC, might be easier to travel if I can not see it from Toronta