From mid-August to mid-April.

The best chance of catching the northern lights (a.k.a. aurora borealis) is during the first few weeks of winter. Ideal viewing conditions consist of dark and clear nights (preferably moonless) with a magic window between 10 pm and 3 am. It’s best to try to leave the city lights behind you and head for the hills.

Although the Northern Lights are visible from mid-August to mid-April.