Toiletries and Medical Supplies:
Umbrella for travelling anywhere in Malaysia. It can be hot (30'C), and it can rain. So it serves dual purposes.
Miscellaneous: I would say right now...it's terribly hot in the early afternoon (that is from 10am to 3.30pm; approximately); then it rains cats and dogs from 4.00pm to 7.00pm.
Normally after a hot, humid day, it will rain at night.
The monsoon coming from the Straits of Melaka is from April to September while the monsoon from the South China Sea is from November to March.
We would be experiencing the Sraits of Melaka monsoon.
You may wish to carry a small umbrella or a raincoat when exploring KL, unless you don't mind getting wet or stranded in the downpour.
During the rainy season, usually rains in the late afternoon, if not the entire day! And it might be heavy - roads will become flooded in the matter of minutes! Be careful if you're wearing flipflops, they might be carried away by the rushing water!
No matter wether it was the rainy season or not an umbrella is always a must when travelling to KL.
once I almost got stuck at KLCC cause it started to rain and I had no umbrealla with me...I had to take a taxi back to my accomodation(which is like 15 minutes walk away from the KLCC).
Luggage and bags:
Water-proof small-sized backpack will be good where you are walking about out in the city. Because it'll rain without alarm. As for luggage, water-proof is still the best!
Clothing/Shoes/Weather Gear: Umbrella will be a good thing to bring along. Backpackers might wanna consider raincoat. Cottony clothing. T-shirts and shorts. It doesnt really get that cold. But a sweater might be useful sometimes. Sandals are so important! Dont' forget your flashy clothes if you love partying. You can party even if it rains out there.
Toiletries and Medical Supplies: Cold remedies. In case you catch a cold.
Miscellaneous: It's easy to think that visiting a tropical paradise.... the last thing you'd need is an umbrella! Well, not the case if visiting KL during the rainy season of November to January.