Mentawai Surf Season, Surfing Conditions Mentawai- Waterways Travel
The Mentawai are in western Indonesia, just below the equator, so these islands are generally wetter and more lush than Bali and the islands further southeast.
The Indonesian archipelago stretches along the equator between the hot, dry Australian land mass to the south, and the hot, wet Asian land mass to the north. Indonesia’s climate is tropical and in the Mentawai there is little difference in the length of a day year around; but because of those land masses lurking above and below, Indonesia’s seasons divide in two: wet and dry.
The wet season begins in October and lasts until March, with the peak rainfall measured January and February, when high pressure flowing south from the Asian mainland combines with humid air from the Indian Ocean to bring rain throughout the archipelago – although the northern and western islands get more rain than those in the south and east.
Prime season for swell in Indonesia is the southern hemisphere winter - March/April through September/October - when low pressure systems off Antarctica and the Indian Ocean pulse ground swells toward the equator. These ground swells travel for thousands of miles, allowing them time to “unwrap,” organize and march onto the reefs of Indonesia as perfectly groomed lines.
Winds are also a factor to be considered. May through Aug/Sept typically sees easterly trades which are favorable for many of the main breaks. November through February generally sees northwesterly winds, which may not be favorable for the big name breaks, but there are waves that favor this wind direction. The shoulder or transition months of March/April and September/October will experience light and variable winds due to the changing of seasons. These months often experience glassy conditions and can be the best time to sample a larger variety of waves.
Although most of the rain falls during the wet season, rainstorms can occur at any time of year. Air temperatures range between 75° and 85° year around and water temperatures are always in that same range.
So, when is the best time? Like with so many questions the answer is: “It depends.” It depends on your desires. If you want big surf with favorable trades, May to September is probably best. If you want to experience some glassy conditions and get a few more rights and less people (but possibly sacrifice some swell size) March/April or late Sept/Oct is probably best. If you don’t mind rain but good surface conditions and smaller, clean surf with nobody else around: give the off season a try, from November to February.