Langøya is mountainous, with mountains reaching 400–700 metres (1,300–2,300 ft) above sea level, the highest is the 763-metre (2,503 ft) tall Snykolla. There are also lowland near the coasts around the island, and in some valleys, some of it is bogs. The treeline is around 300 metres (980 ft) above sea level on Langøya.
The total population on the island is about 15,600 and the largest population center is the town of Sortland (population: 5,600) and the next largest population centre is the village of Myre. Langøya has been settled since the stone age.
Langøya has a subpolar oceanic climate (Cfc), with very mild winter for the location north of the Arctic Circle. The warmest temperature recorded on the island by an official weather station is 31 °C (88 °F) at Kleiva in Sortland municipality in July 2018. The weather station near Stokmarknes Airport, Skagen is located on the southern part of the island and has recorded temperature since June 1972. Data for extremes available since 2004, there might be warmer or colder temperatures recorded before 2004.
Climate data for Stokmarknes Airport Skagen 1991-2020 (3 m, precipitation 1961-90, extremes 2004-2020)