Because Bali lies just south of the equator, its seasons are defined by rainfall, not temperature. The period tourists call "summer" aligns with the dry season, roughly May through October.
Daily heavy downpours, high humidity, occasional flooding, and rougher seas. However, landscapes are lushly green, waterfalls peak, and accommodation prices drop.
June–September is peak season: ideal weather, but highest prices and crowds. May and October offer a sweet spot of good weather and fewer visitors.