The Lower 48
Northern lights viewing conditions are seldom perfect in the Lower 48 states of the U.S. That said, people who can get as far north as possible have a better chance of seeing the skies lit up on a clear night. Taking a peek at the daily aurora forecast can be helpful. However, these forecasts seldom look more than a week into the future, so a trip north is not something that can be planned far in advance.
The Upper Peninsula of Michigan, northern Minnesota, Wisconsin (pictured), the Dakotas and Montana are places that will give tourists the best odds of seeing a spectacular lights show. But, again, the window of opportunity is brief and conditions have to be clear (as in cloudless), so there are no guarantees, even if you are able to travel north on short notice.