In some ways, Songkran, a festival that coincides with the Thai New Year (in mid-April), is the cleanest entry on our list. It is basically a countrywide water battle fought with buckets, hoses and squirt guns. Pastes, flour and powders are also thrown and most people end up coated in a layer of these substances, at least until they get the inevitable bucket of water over the head. This is not an event that you can choose to participate in. If you are on the street in any major city and town in Thailand, you are fair game for a splashing. Yes, even if you are in your finest duds heading out to a dinner date, the Songkran celebrators won't spare you.
The Thai capital of Bangkok is one of the hottest cities on Earth, so at least temperature-wise, getting wet is not unpleasant. However, since you will get wet and “pasted” every time you go out side, this can be a frustrating time of year to visit the Land of Smiles. The water fight has its origins in the practice of washing Buddha statues during the New Year. It is still possible to see more traditional Songkran practices like this in smaller towns all around the country.