Thailand is a tropical country with its typical high temperature all year round. 25-30°C in the cold season, 35-40+°C in the hot season and 30-35°C during the rainy season. Humidity is always high, even though it's easier to bear during the cold season during which the sun shines. The rainy season is characterized by scattered heavy showers now and then everyday, cloudy weather almost full time. The water is around 26°C.
Wind direction makes for gusty conditions, with wind coming over land. A true NE direction can be good. Generally wind will be stronger on an easterly direction due to throttling effect but gusty. Works only during NE monsoon. November to mid February: the Northeasterly monsoons, wind ranging from 8-18 knots in a NE, E and tending SE in January and February direction. Wind blows in cycles averaging 6-10 days at a time. Wind is generally strongest in the morning/lunch time and decreasing in the afternoon. There is still some rain throughout November until mid December, this can affect the steady monsoonal winds, create sometimes squally conditions, but generally the wind is very consistent. Mid February to end of April: summer time, hot and no rain. If you want wind go to Hua Hin. Mid May to August: the Southwesterly monsoons, winds ranging from 8-20 knots, the rainy season during this time, more rain in May then decreasing. Wind comes from the SW to W and becomes more northerly as the season moves progresses, wind can be very good but is generally less consistent than the NW monsoon. Be careful of any storm fronts coming through, wind can increase from nothing to 40 knots suddenly. September to October: change over period, possibly no wind and plenty of rain.
Koh Samui has a great nightlife you can choose between Chaweng and Lamai beaches, they offer pubs, clubs, go-go bars with the occasional foam parties and monthly beach party thrown in.
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