While there definitely is a "season" for auroras, ie they are more likely to be visible during spring and fall, they can be seen at any time of the year if the conditions are right. Two of the best displays I've ever seen have been right in the middle of summer. One in late July, one in early Aug.
This one was in May:
This one was in August:
The last one there from August was from one of the best nights I had seen. I spent it on a pontoon boat with friends, and by the time I got dropped off at my cabin, it had definitely died down. I took that picture on my dock, and with a little wave action, the focus is a bit off.