rainey season

when is a rainey season on thailand?when is a best time for travelling?winter or spring?

Winter time is the best.

Koh Samui and Koh Phangan will be reached by the north east monsoon, but this are normal only short and heavy rain showers for 1 - 2 hours.

I guess you will welcome this rain as it brings some freshness to the hot climate.

Leelo - where are you coming from.....there's no spring summer autumn winter in Thailand.
Thailand has 3 seasons....Cool Dry Nov - Feb, Hot Mar to July -ish and Rainy Aug to Nov.
But different areas have different characteristics....Samui and surrounds gets a double rainy season.
What do you mean by spring etc....Feb is mid-summer in Oz.
The wet season in Thailand is not usually too bad....showers with warm clear periods in between. Koh Samet is meant to be the driest island in the wet.
There has been a typhoon warning for Bkk for Sunday, which could mean some serious rain and the accompanying floods - we'll see!

Now is the wet season. Check out the Bangkok Post or The Nation and you'll soon see the extent of the flooding.
When I left home last Monday the rivers were well up in Ayautthaya.