Northern lights

As Grímsey has few inhabitants, light pollution is therefore not an issue. Conditions to enjoy northern lights are good from late September till end of April during the dark time of the day.

The Northern Lights – also called Aurora Borealis – are one of the most spectacular shows on earth and can frequently be seen in the north of Iceland on clear and crisp nights. The Northern Lights occur high above the surface of the earth where the atmosphere has become extremely thin, in an altitude of 100-250 km. The Northern Lights exist in the outmost layer of the atmosphere. They are created by electrically charged particles that make the thin air shine, not unlike a fluorescent light. They can be seen in aurora belts that forms 20-25 degrees around the geomagnetic poles, both the north and the south.

White and green are usually the dominant colors of the Northern lights but sometimes there are considerable color variations, as the pressure and composition of the atmosphere varies at different altitudes. At extremely high altitudes where the pressure is low, there tends to be a reddish glow.  At lower altitudes, where there is higher pressure, their impact-irritated oxygen molecules may glow with a greenish tinge and sometimes there is a reddish lower border created by particles colliding with nitrogen molecules in the immediate vicinity.

Let the personnel at your accommodation know that you want to experience the northern light and ask for to be awakened if they appear.  Northern lights often appear in short periods of time e.g. 5 – 15 minutes. This phenomenon can come and go, very unpredictable. So patience is important factor in order to experience them. The Icelandic Metrological Office has a web page predicting likelihood of northern lights; this is no 100% science so we recommend you to look even though the odds are not high.  The key factors for seeing northern lights are darkness and a view to a clear sky.

Probability of northern lights - The Icelandic Met Office.