Jakarta Travel Guide - Weather
The wet season lasts from October to April, but the heaviest rainfalls usually begin in December and stretch to late February when the rains begin to taper down. It is best to avoid visiting Jakarta during the heavy rainfall months as the city is prone to flooding.
The dry season is from May to August but there is not much difference in temperature to the rainy season. Although it is the dry season there are occasional short bouts of rain. The best time to visit Jakarta is between May and September.