Summer (June–August) is the obvious season, when the Grímsey ferry runs most reliably, whale watching is at its peak, and the Great Fish Day festival takes place on the second Saturday of August. The midnight sun in late June and July means that Grímsey, right on the Arctic Circle, gives you the most dramatic experience of the phenomenon in Iceland.
Winter offers the possibility of seeing the Northern Lights over the fjord and mountains, and the area is much less visited — Dalvík in January is a very different place from the summer tourist stop. The Grímsey ferry runs year-round but less frequently. Mountain roads and passes in the Tröllaskagi area may be closed by snow from October through April.