I was in Hatyai in November 2007 during Loykrathong festival. The city of Hatyai had a Lantern Festival in the area next to Diana Department Store. It was packed with visitors. There was a performance on the center stage. The lanterns were really colourful. Admission is free and too crowded to my liking. If it was less crowded, it would be an enjoyable walk in the middle of the colourful lanterns. They came in different shapes and colours. Good photo opportunities. However, I am not sure if this is a yearly event. But I hope it is.
Loykrathong festival is the event that Thai people make a wish and release beautiful mini (or some large ones!) flower floats, known as 'krathong' to the water. It happens after dark. I have to admit that Thai people really know how to celebrate festivals. You can buy these 'krathong' from the street. You lit a candle and incense in the middle of your krathong and then release it to the water. I visited Loy Krathong festival in Prince of Songkla University.
Please check the actual date as it changes every year. It is sometime in October or November each year. Wat Hat Yai Nai is also another place to celebrate Loy Krathong festival in Hatyai.
The not to be miss show is the Thai Show. I cannot remember the name of the place, but ticket booth are many around in town, even at most hotels. I paid 300 bath for the night show that come with seafood dinner too. Very good cultural shows, done by 'middle sex' dancer. But you must prepare to leave fast before the show end, as they will come down to audience, to collect tips, and to male visitors, becareful when you go gents, the 'cleaner' in there are for money too. They offer 'servces' .
Songkran Festival is the traditional Thai New Year celebrated on April 13th. The celebration usually last for 3 days or longer vary in different areas.
By no means the main attraction of Songkran, but certainly the most spectacular, are the water fights which take place across the country. Water supplies will be prepared by the organizer around the town center to ensure all will never 'out of bullet'.
It's impossible to keep away from the wet, the only choice is to join the 'water war' and defend yourself using water gun.