Weather?

Sort of depends what day it is.
Rainy season is with us so there's a good chance of rain.

As for floods, depends on the district you'll be in.
Only bits of Jakarta flood but that doesn't make a dramatic enough news story.

January is the month with the heaviest rainfall and the city can grind to a stop within hours of a storm. But it's still hot which is nice.  Getting to the city can be hard work if there are floods as the road to the city from the airport can flood.  The traffic in the rain is shocking but if the city is under water then there is no traffic nor anywhere to go because of it.
Where will you be living?

hellow my friend,

thank you for replay bro,i will stay @ Le Meridien Jakarta, hope its nice area!

It's a great place to be but I wish you lots of luck in the rain and traffic. Don't leave anything to the last minute there. That part of the city either floods or all the roads to it will.

The best of luck! I hope its not going to rain that day

I would like to thank all ya'all for taking your time to answer my question ,  (Party Hard Dance In The Rain)

maybe it will be raining today...in the evening...   . if it floods around your hotel...you might want to stay at Hyatt, it is right next to ex and across Grand Indonesia.

I hear thunders..