These natural light displays in the sky – often referred to as Aurora Borealis – occur in a zone extending over Iceland, northern Scandinavia, and Greenland, continuing over northern Canada, Alaska and Siberia.
The number of sunspots on the surface of the Sun is the main cause for the appearance of the auroras. The amount of sunspots follows an 11-year cycle, which is expected to reach its peak in 2016. The aurora strength is based on the number of occurring sunspots, the more sunspots, the better chance of the auroras appearing.
As the cycle gets close to its maximum peak, the general conditions for viewing the northern lights in Iceland are exceedingly good, although their visibility is always subject to clear sky and dark nights. Consequently they can not be seen in Iceland during the bright summer nights but the period from mid September to early April offers the best possibilities.