The weather on Groote Eylandt is tropical with hot humid and wet summers marked by thunderstorms. Summer temperatures range from 25 to 40 degrees Celsius. The winters are dry and mild with temperatures from a rare 10 to 30 degrees.
The vegetation is mostly tropical savannah woodland (string-bark eucalypts and Darwin woolly-butt), with patches of monsoon vine forest, areas of pandanus and paperbark wetland and strands of cypress pine. Casuarina and banyan trees give shade along sandy beaches. Animal life is prolific. The land is not used for primary production and there are no cattle on the islands.
The marine environment around Groote Eylandt is close to pristine. The environment features clear waters, abundant marine life, easy access, large animals such as dugong, crocodiles, turtles and manta rays. The area is particularly well known for its fishing and a number of charter boats operate around the islands and the Groote Archipelago.