The dry season in Indonesia typically runs from April to September, but can vary from year to year and shoulder season can show variable characteristics and have light winds. The dry season is typically called the ‘on’ season because the consistent SE trade wind that blows almost every day from mid morning is offshore for a lot of the premiere surf destinations in Indonesia. The dry season also aligns with the southern hemispheres winter so constant long period swell are created by the storms that frequent the roaring forties between South Africa and Australia this time of year. The coast of Indonesia very rarely goes flat during this season. The trade winds are the strongest in the middle of the season around June and July and are typically stronger the further south you go. In this season the Mentawai region will see light to no wind, and the storms become less frequent meaning that the conditions are more consistent.
The weather in the dry season is typically more consistent and it may not rain for months on end, significantly changing the landscape from green and lush to brown and barren, particularly in the more southern regions like Sumbawa, Sumba and Rote.
In Bali surfing during the dry season means a lot of your attention will be focused on the south western region, including the Bukit Peninsula, the Kuta area and Nusa Lembongan as all these regions are offshore in south-east winds. Waves like Uluwatu, Impossibles, Balangan and Shipwrecks very rarely go flat this time of year and have ideal conditions all day. The consistent long-period swells mean that wave like Padang-Padang and Kuta Reef can break quite consistently.