For Songkran in Bangkok, pick a spa by where you are leaving the streets rather than by name. If you start at Siam Square, Treasure Spa and Nature Thai are in the same zone; for Silom there are Health Land Sathorn and Silom Edge, for Khao San there is Aromee, and for Nana there is ThaiThai.
After a water fight, legs feel heavy and skin runs hot. Treasure Spa has a package with a cooling jade facial, and Health World Onsen offers a cold plunge pool and ice room, both suited to settling the heat of the day.
Choose timing by closing and last admission. Health Land Sathorn opens at 09:00 and closes at midnight with last admission at 21:00, and ThaiThai Nana opens at noon with last booking at 23:00. If you plan to be in the streets by day and book in the evening, these two give the most room.
If getting soaked worries you, read the shower rule first. Health Land Sathorn charges extra for showers after Thai and foot massage, One More Chit Lom allows showers only with aroma massage, and Aromee has no shower.
Songkran fares and hours can differ from usual. Before booking, check the current hours, last admission and child and pregnancy rules on each listing.