I have been to Ko Samui in August and the weather was great, Ko Samui is a great little island , it is much more built up than when I first went in 2000 , there are lots of good restaurants and some great beaches, I wouldn't visit Phuket in August at it is rainy season there.

That would explain the price difference between holidaying in the two places in August. The prices for Phuket were looking very tempting but Koh samui was more expensive

The prices are very silly in Phuket for the dry season so hence that's why we have ony ever gone to Phuket in the wet season. It's always (well! nearly always) been busy and I'd hate to be there when the crowds arrive as I'm not a big crowd lover. Hotels are often 2 for 1 in the low season. We are going back to Phuket in October and got a great accommodation deal with an online travel agent who was fantastic (specialistholidays.com.au) All dealings over the phone and prompt email conformation. TA was brilliant when I decided to change our hotel (We was booked at the Metadee but I decided that after reading some reviews it was too out the way for me) so now we are going to Kata Beach Hotel. We have stayed there before so know what to expect. Last time there I made friends with 4 Russian ladies who were a bit naughty and reserved 4 sunbeds in the shade and 4 in the sun They were all knitting woollen hats for the Winter

Normally we are DIYers but in this instance it has been a LOT cheaper to go through an agent. I have since priced our hotel with a few hotel booking sites and they come in at nearly $AU800 dearer as they don't appear to give the 2 for 1 deal.

Only been to Koh Samui once and it unseasonably bucketed it down. The main street in Chaweng was flooded and the hotel was sand bagged. Turned out we was on the edge of a cyclone in the Philippines and we was getting the depression/rain. People were clambering to leave the island but all the planes were fully booked, then one day the sun came out and all was well with the world. In the meantime we'd moved over to Lanai to a cheap and cheerful $50 a night and had a wonderful holiday in the sun .

Cheers Geri

In answer to "What would you say to Thailand 1st 2 weeks in August" - the answer would be - yes please

However, i'd stick to Samui for August.

Though pay attention to what Gerib says - off season can see some amazing prices (2 for 1's etc) - particularly at the beginning and end when there is less risk of adverse weather -

i.e. Phuket & West Coast (and Bali & Langkawi & Penang & Lombok!) - May & October
Samui & Phangan - May - June

etc etc

Just returned from Thailand (15th Aug).
We stayed in Koh Samui, 6 days in Chawang, 4 days in Bophut, 6 days in Lamai, 2 days in bangkok, also visited Koh Phangnan.
Personally we preferred Lamai and Bophut for the beaches and sea, did'nt like chawang beach and found the sea dirty and shallow. It may have just been the area we stayed in.
The weather..........well, no 2 days were the same apart from the heat. We had torrential thunder storms, short downpours, and some showers. Most of the time it was very,very hot and sunny. Sometimes the rain was a welcome relief.
We did move hotels (long story !!) and realised that the prices changed on 1st August when it became 'high season', so take this into consideration when booking.
Any questions don't hesitate to ask.