It is very hot and sticky in Kuala Lumpur.
Luckily the shopping centres and even some of the street vendors have icy cold aircon - the best aircon i have ever experienced.
Travelling must still go on and i recommend that you have a bottle of water with you at all times. You will be amazed at how fast you can go through that bottle.
The city does go on at night so stay inside during the hot hours and venture outside early morning and at night.
As it was my first time in kl we were out for most of the day, coming from australia it was bearable the weather.
As Malaysia is a tropical country, we have rain and shine all year round. Towards year end, it's usually monsoon time and there's lots of rain ! So, bring rain coats and those brollies ! Best to avoid the east coast of the peninsular of Malaysia...
Generally warm to hot throughout the year with temperature ranging from 21C to 32C. Humidity is high all year round.
A rough guide to the seasons is as follows:
October to February (Monsoon rainy season).
March to September (Drier and hotter season).