January weather VFR in the tropics isn't a nice place to be. Be prepared for some rather long diversions around lines of cells. The intensity of the ITZ varies from day to day, but that time of year is usually in a line east west just south of YPDN and streches across to Bali. Be prepared to carry a minimum of 60+ holding on any destination. I have held at Kupang for 90 mins waiting for the field to open to IFR landing minima. Weather information is hard to get, but Kupang and Bali have Met Offices. Bali is especially good in that respect.