The weather in Bali is generally sunny all year around with the temperature ranging from 23 - 27 degree Celsius (74 to 88 degree Fahrenheit) during the day to 24 - 27 degree Celsius at night.
Cotton or lightweight clothing is suitable for daywear
Proper evening attire is recommended when dining in restaurants
Light cotton, viscose or silk clothes are most comfortable to wear in the this warm climate (linen is usually too heavy)
Swimming attire or shorts or tops that do not cover the shoulders should not be worn outside the hotel areas. Sloppy or untidy clothing should also be avoided, because clothing is an indicator of social status and you will be treated much better if you are dressed cleanly and modestly.