Just 8° south of the equator, Bali has a tropical climate - the average temperature hovers around 30°C (mid-80s°F) all year. Direct sun feels incredibly hot, especially in the middle of the day. In the wet season, from October to March, the humidity can be very high and oppressive. The almost daily tropical downpours come as a relief, then pass quickly, leaving flooded streets and renewed humidity. The dry season (April to September) is generally sunnier, less humid and, from a weather point of view, the best time to visit, though downpours can occur at any time.

There are marked variations across the island. The coast is hotter, but sea breezes can temper the heat. As you move inland you also move up, so the altitude works to keep things cool - at times it can get chilly up in the highlands, and a warm sweater or light jacket can be a good idea in mountain villages such as Kintamani and Candikuning. The northern slopes of Gunung Batur always seem to be wet and misty, while a few kilometres away, the east coast is nearly always dry and sunny.

Air-con is not really needed on Bali at night. A cool breeze always seems to spring up in the evening, and the open bamboo windows, so common in Balinese architecture, make the most of the light breezes.