The Indonesian climate is almost entirely tropical. The warm waters of the ocean surrounding the archipelago ensure fairly uniform temperatures on land and there is little seasonal variation. There is also little difference in daylight hours from season to season. Indonesia experiences hot, humid weather throughout the year, especially in coastal areas. The inland highlands are somewhat cooler. The climate of Indonesia is dominated by heavy monsoon rains, which occur between November and March, or to be extra safe between October and April, often causing damage and making local travel difficult (the rainy season is also the worst time for some mosquito-borne diseases). The best time to travel to Indonesia is therefore during the dry season, between May and September. The rainy season varies in impact from island to island and although some areas experience extreme conditions and flooding others are less dire and can safely be visited during the rainy season.The busiest and therefore most expensive times to visit Indonesia are in the holiday periods: at the end of Ramadan, when domestic tourists fill resorts and prices escalate; at Christmas; and mid-June to mid-July, when graduating high-school students arrive in hordes, mainly in Java and Bali.
