In theory, the Northern Lights appear from late August to mid April, but you are much more likely to see them from late September to late March, when there is less light.
In the high Arctic, the sun never rises in December and early January so while you might have more hours in which to see the lights, you will be very limited with the activities you can do during the sunless days. The days will be much longer in February and March.
In December, families flock to Lapland to meet Father Christmas – so this is not the best choice of when to see the Northern Lights if you’re seeking a peaceful retreat with few crowds.
October and November tend to be cloudier, especially in northern Europe; you need clear skies to see the lights. The aurora is present on 80 percent of clear nights – so this is the key factor in increasing your chances of seeing it.
The lights generally appear between 6pm and 4am, although the highest probability is around 10pm-11pm. But they do materialise with no warning – so keep your eyes on the sky!
The lights are not all that bright; a full moon will bleach them out. For this reason, many tours are scheduled around the new moon – check your dates to ensure this is the case.
Forget seeing the lights in May, June and July – the midnight sun ensures they are well hidden.