Bangkok is a tropical city so it's pretty warm throughout the year! Avoid April, May when the weather is especially hot and sticky (temperatures around 34 C) although one of Thailand's most celebrated festivals - Songkran, takes place in April and involves lots of water throwing to cool down. Best time to visit is from October until February with temperatures around 25- 28 C light breezes and only the occasional shower. June to September still has plenty of sunshine and is much cooler (around 24-28 C) but is the season for rain and is actually quite refreshing! The advantages are less visitors and better hotel rates. What to Wear Forget the tight pants and clinging dresses (at least for the day) and go for light, loose cotton clothing. When visiting temples, certain museums and the Grand Palace remember to dress appropriately. Shorts, singlets, spaghetti straps and open backed sandals are not acceptable