Further to your original post thebeargirl, the elevations in Thailand are very modest compared to anything in Yunnan. The highest mountain in Thailand is only as high as the western hills surrounding Kunming, so you won't need anything more than a light sweater.

The weather in Thailand in the dry season, covering all of northern, north eastern and central Thailand is superb. The chance of rain is almost nil, the visibility is superb and temperatures average around 28 degrees C in Chiang Mai, 31 in Bangkok and minimums are around 17 in Chiang Mai and 21 in Bangkok, although 25/33 even in December or January is not unknown in Bangkok. Basically, it's hot, sunny and less humid and cooler than other times of the year but that's it.

I doubt that the water quality in Thailand could be any worse than China. I would never drink tap water in China because that would make one very sick, and I would advise the same in Thailand. If you have a weak stomach, brush your teeth with bottled water only.

Thailand is generally safe, but as a freer country than China with less police control and far more tourists and expats, you'll find things a bit different especially in nightlife areas. While by and large safe, don't attract the wrong people or you could get in trouble.

As soon as you arrive in Bangkok, you'll see people from India, Europe, Africa and other places, whereas in Kunming you might see 3 foreigners roaming downtown, in Bangkok half of all people in the central shopping areas will be foreigners. The difference between Kunming and Bangkok in this respect is like night and day.

Finally, never ever lose your cool in Thailand. Nobody will help you or talk to you again if you do. Getting visibly angry might work in China, but it gets you nowhere in Thailand. You'll almost never see Thais get visibly angry, so I would advise you to heed this crucial piece of advice.

On the subject of exchange rates - I know for a fact that the by far the best exchange rate when using a UK debit card is by just taking money out of an ATM - then you get the inter-bank rate, which is way better than going to a money changer. I don't know how this compares to other country's cards.

Also I have no idea whether the ATMs accept UnionPay but I'd be very surprised if they don't, seeing as tourism is a key industry in Thailand and Chinese tourists are 越来越多。

@chris8080, many ATMs do, but not all. It's still better to come equipped with a VISA or Mastercard debit or credit card, which are accepted everywhere.

BTW many Chinese ATM cards such as the Great Wall Card issued by the Bank of China, which I possess state clearly in English that the card can only be used inside China. Therefore, I recommend asking your bank in China to see if they can issue a VISA or Mastercard card (a credit card would probably not be available to a 20 or 21 year old non-working student though, so it would have to be a debit card), although Unionpay should work in many tourist areas but probably not in more remote places, whereas VISA and Mastercard will be accepted everywhere.

@thebeargirl, interesting you mentioned tipping in Thailand. In China no one tips so I didn't think you would understand the concept being Chinese yourself. Basically it works like this:

In China: no tipping, ever.

In Thailand: leave some spare change if it's an expensive meal or tip about 20-30 Baht. Never tip street vendors or for cheap meals. Tipping hotel staff is at your discretion but generally only in more expensive hotels (4 or 5 star) and even then it's not absolutely required.

In America: Always tip about 10-15% in restaurants and hotel bellboys etc.

As you can see, tipping in Thailand is somewhere in between the extremes of China (no tipping) and America (tipping everywhere).

It is possible that Union Pay cannot be used outside China as part of China's currency control. If that is the case it will outside of the scope of Union Pay's licences.

@Yuanyangren, isn't it difficult for a foreigner to get a Visa or Mastercard issued by a bank here?

Does anyone know if banks (or other places) issue PRE-PAID Visas or Mastercards?

Regarding the exchange rate when drawing money from ATMs...

Yes, usually the exchange rate you get is very good and the interbank rate. The bad thing is usually the fees your home bank charges, which can inflate your exchange rate dramatically. Now I don't know what the fees are for Chinese banks, but from my experience Chinese banks price gouge you for everything (for example a fee for withdrawing money from their ATM in a different city within China), so I imagine you should be very careful when drawing money out of ATMs in Thailand. Find out in advance whether the fee for doing so is a flat rate (i.e. 50RMB per transaction, in which case you should draw the maximum out of an ATM each time) or a per 100RMB changed (in which case it doesn't matter, but try to draw out, for example, 195 RMB each time so you aren't charged too much).

Best bet - find out in advance. If you are going for 5 months, it may pay to shop around to find the bank that will charge the least fees, get an account there, transfer money before you leave and use that account as your Thailand account. Seriously, it may save you hundreds of RMB and only take a few hours of research/hassle, so I would do it.

My bank only charges 1 pound each time, but I know people from other countries who get charged more than 10 times that.