Langkawi is an archipelago of 99 islands in the Andaman Sea, some 30 km off the mainland coast of northwestern Malaysia. The islands are a part of Malaysia’s Kedah state, but are adjacent to the Thai border. By far the largest of the islands is the eponymous Pulau Langkawi with a population of about 45,000. The island is a declared duty-free zone.
The peak season is from December to March when moonson at the eastcoast shuts down most of the Islands there (Perhentian etc.). This makes Langkawi a good island alternative during that time period. Generally though, Langkawi can be visited all year around.
Pulau Redang (or Redang Island) is a beautiful tropical island off the east coast of peninsular Malaysia in the state of Terengganu. Most travellers visiting Redang come on pre-booked packages from one of the resorts on the island. It is a more up-market destination than Perhentian Islands.