The Northern Lights are determined by an 11-year solar cycle. At the peak of this cycle is a “solar flip,” where the sun’s magnetic fields have a complete field reversal. This “solar flip” should be the time when conditions to see the Northern Lights are at their best.
We already had one peak of solar activity, during the winter of 2011-12, and there were reports of incredible sightings, which showed off the full range of colors that can occur in the Northern Lights. A second peak of activity is expected soon, bringing excellent possibilities for Northern Lights through the winter of 2015.
Experts are gaining accuracy in predicting the times of peak Northern Lights activity, so this is a great time to book a trip to one of the viewing destinations. Even though this should be a superb time, there is no guarantee of seeing the lights, and there is always the possibility of cloud cover which can block the view. It’s also possible to see the lights even when solar activity is at a low point, but the displays are usually less impressive. The appearance of the lights is unpredictable, but in general the season goes from early October through late March. October, November, February, and March are usually the most likely times to see the lights.