As Grímsey has few inhabitants, light pollution is not an issue. Conditions to enjoy northern lights are good from late September till end of April during the dark time of the day.
Grímsey is surrounded by the North Atlantic Oceanwhich is cold arctic water. It is possible to take a swim in the ocean; it is clean - but cold, about 8°C during summer and 4°C during winter.
The Thermal Pool in Grímsey is open 4 days a week, the pool is a indoor pool and the facilities also includes a hot tub, showers, toilets and wardrobe.
Grímsey is 5.3 square kilometres and 5.5 kilometres long, it is comparatively flat, lowest on the West side by the harbour and village and highest on the East side rising up to about 105 meters above sea level. There are several different hiking trails/paths to choose from.