Songkran is the traditional festival that celebrates Thai New Year. All over South East Asia similar festivals are held. Songkran has its roots in Indian religious mythology. It involves a complex story involving a bet between the gods. For the Brahmins of India Songkran also marks the date that the rising sun re-enters the constellation of Aries.
Traditionally in Thailand the date in April marks an important time in the agricultural calendar. Time was spent to give thanks to Buddha for the last harvest and to propitiate Buddha for a good future harvest. At this time scented water was sprinkled on the hands of elders and monks. It was a gentle holiday with gentle and respectful obeisance.
This is not the impression that foreigners gain from Songkran nowadays. For a start the astrological significance of the festival has been lost by abandoning the lunar calendar dating. Instead the festival date is fixed as falling from April 13th to April 15th. And also the religious and cultural significance of the festival has been lost. Songkran in Sukhumvit is not a particularly religious event. It is about drinking, throwing water and having a good time. Everyone tend to join in and there is little way to avoid having water thrown at you on the Sukhumvit Road.