As a result of its offshore location, the Anambas Archipelago tends to blessed with decent winds pretty much year-round. Whereas pleasant sea breezes tend to blow during the relative lulls between the two main monsoons, the northeast and the southwest monsoon seasons are characterized by strong winds, generated by the perennial temperature difference between the landmasses of China to the north and Australia to the south.
During the northeast monsoon, November to March, for instance, wind surges from the northern South China Sea, barreling their way south, not only sweeping the sea water surface into serious oceanic swells, but gradually displacing the warmer moist summer air around the Anambas region.
Now, whilst the initial months of this monsoon, November and December, bring copious amounts of rain, once the atmosphere above Anambas has stabilized, it's primed for seriously powered up windsurfing; northeast monsoon winds can get up to a punchy 30 knots, and more.
Equally consistent, though perhaps not quite as punchy as the northeasterlies, are the winds that blow once the southwest monsoon has taken over the arena. April and May tend to be transition months, but from June onwards, the Anambas islands are pummeled by recurring trade-type windy spells that can last a week or so before tapering off for 7-10 days. Typically, these recurring southwesterlies tend to be 15-20 knots, ideal for freeriding, freestyle windsurfing, as well as for bump and jump sessions. That said, there are always a few red-hot 25+ knot SW days peppered in, so stand by for these if you're into gnarly conditions.
September and October are, once again, transition months, typified by lighter, more erratic winds, i.e. calm and windy weather taking turns, as well as local thunderstorms. But good winds can certainly still be had during these wildcard months.
Bottom line, Anambas is a bit of a mystery spot that few will get to see, and fewer still get to windsurf. But if you're in the South East Asia region during windy season and you're aching to get some high-octane windsurfing under your belt, head for Anambas!