1

I find you need something warm if taking a night bus in Malaysia. Its either so cold or the aircon leaks.

2

depend on where and when you are planning to go
I'd just use layers and leave heavy jackets home

3

I wouldn't bring a heavy jacket, but a super thin rain jacket will be useful--much better than a bulky, awkward umbrella! They're lightweight and can be squashed into small sizes. I'm not sure what time of year you're travelling, but rain pants of a similar material can also be useful if you're caught in a downpour while trekking.

I also think hiking in the jungle is much better with nylon (or similar material) lightweight long pants and a long sleeve shirt made for hiking. It can get chilly at night (especially in the highlands), but more importantly, it's good to have the extra protection from thorny plants and biting bugs. They also are much lighter than cotton, take up less space, and dry faster. You also look more presentable and blend in better culturally in long pants. I never hike (or even travel really) with shorts or in a t-shirt.

4

Take a light fleece for bus rides and other times when the aircon is on full blast. If you need to get a jacket for trekking buy yourself a cheap light plastic cape locally just before you trek (easily found in supermarkets in Indo for around $3)..

5

Many good points in these replies, thanks.My hiking jacket will not make it on this trip.
Long pants are better for protection of body and also for cultural blend in, very true.
A long sleeved shirt suitable for hiking, I assume that is almost any cotton shirt that can take being soiled a little?
I still have to have something for super-a/c bus rides and maybe a cold evening in higher terrain. I still am not sure I can see myself using rainjacket and raintrousers. If it is daytime and I am walking about I easily get sweaty under it. If it is evening I have reached my destination and can use the umbrella for a short hop out. (I had some "Goretex" raingear before, but I must say I still get sweaty if I use it in the tropics. Maybe quality wasn't good. My Goretex hiking boots are really good, though. maybe feel warm, but seem absolutely waterproof and not sweaty.)
Maybe I'll just buy a simple "Goretex" or plastic rainjacket, that will be light to carry and useful to keep warm. (The one I have now is rather thick, has a lining, many pockets and goes down to the thigh. That makes it too heavy and warm.) using long pants will be good for occasional cold moments.

6

The people who work in outdoor equipment stores reckon that cheaper raincoats are waterproof in the inside and the outside in the tropics - ie. when you sweat it's just as wet inside the gear as outside.

Just stick to a cape or umbrella that lets the air flow. That's what the locals do and they should know a thing or two about the local climate.

7

Navigare, real hiking shirts, like any sport shirt, aren't made of cotton, but usually some sort of polyester, nylon or other blend that is thin, lightweight, and wicks moisture off of your skin. They also often have venting slits on the back and other areas. Cotton is actually not that great when trekking, as it gets heavy when wet, and takes forever to dry.
Some examples here: http://www.rei.com/category/4501436

Rain ponchos (I think that's what Julie means when she talks about "a cape") are pretty effective, but certainly not as versatile and don't keep the chill out as well as having a thin, lightweight jacket. A good rain jacket isn't going to make you all sweaty, and usually when it's raining it can be a bit chilly. Locals use rain jackets all the time if they have the money to buy them--they're superior to ponchos. Also, an umbrella is fine if you're just going around town, but you said you're planning on hiking? Usually when you're hiking you don't want to have one hand tied up with an umbrella, and depending on the strength of the downpour, you'll probably still get pretty wet. And if you're doing any sort of jungle trekking, an umbrella is going to be way too big and bulky for forest trails (and again, you'll want to have both hands free). Nobody uses an umbrella in the forest.

8

That's a good point lukemackin. Miixing with synthetic is better.
I looked in one mall (Sorya) and one market (Thmey) in Phnom Penh yesterday.
Not one thin rainjacket to be found.
A few of these extremely thin and fragile ponchos and one a little heavier "like my granddad had". ("The opposite of Goretex", haha)
I will keep looking today. I think a thin synthetic jacket will give me a little extra warmth occasionally.

(My trekking or hiking is mostly on roads and trails. I mostly walk alone and therefore stay on roads and trails. Occasionally go into the jungle but then with a guide, of course. If the rain comes I use the umbrella. It slows me down, of course. Sometimes it also gives nice encounters with the locals, seeking shelter from the rain. But still, using a rainjacket in heavy downpour in tropical climate, i think you will get wet from sweating and the legs will be wet from rain. But I agree to sometimes seeing locals using ponchos. heavy rains in Phnom Penh the last two evenings. The street sellers use ponchos, even those pushing carts. Thats a tough working environment, flowing street water levels way up on your calf, wearing a flashlight strapped to your head, pulling a big cart in all-covering raingear, in tropical climate. Some wear boots but I think the water levels pass the boot top sometimes. Also the risk of stepping into a hole. i saw one pedicab driver falling over in the high water, pushing his pedicab. When the water dries, it will attract mosquitoes to your legs if the water was dirty ...)

Thanks for many good pointers.

9

I spent about one hour at Orussei market in Phnom Penh today, it is a big place. I had downloaded a picture of a thin nylon jacket to my phone, that I showed. I also asked for rainclothes which they understood.

I did not find anything! They had long pants in nylon but maybe not waterproof, but no matching jackets. Jackets were thicker.

If you don't find something at such a big market it is usually not because it is not there. It is because you couldn't locate it. But at least you can say it is not a big thing with rainclothes. Motorbike drivers and pushcart vendors/collectors use it since they have to be out in the rain and work with both hands busy.

But tropical rains are often so heavy that you really need heavy duty stuff to withstand them. They also often pass within 1-2 hrs. Not the drizzle all day we have at home, at least in my country, sometimes.

I think I will just stay with the umbrella and seeking shelter until the rain stops. At least until I find a very lightweight waist long (short) jacket.

10

Yeah, seeing as you're already overseas, you'll probably only be able to find the quality stuff in shopping malls or other higher end sporting goods stores. Just in a local market, they'll probably not have it, as the good stuff is not cheap. Probably a poncho is your best bet at this point.