1

Hi Lubeg, Introduce myself my name is Mery. I live in berastagi, North Sumatra. About the raining season. We can't predict the weather. Sometimes, you will find good weather in December, but sometimes raining. Warm regards, Mery

2

Rainy season usually just means that it rains hard for an hour or two in the late afternoon. Very rarely will it last the whole day. And often, in my part of Sumatra anyway, there is a mini-dry season in January. But, as carilch says, no one can really predict the weather anymore. So, whatever season you visit, you should be prepared for rain at any time (have a light rain jacket or poncho and a rain cover for your bag with you, at the minimum). It is the tropics after all.

3

Hi Lubeg,
I spent 28 days in Aceh Province, Sumatra in January this year and got wet once!
I have just posted a more detailed reply to the thread after yours if you would like more information.
Have a great trip