The island of Bali sits ate between 5 and 10 degrees south latitude below the equator. As a result, weather is generally calm for most of the year. Daytime temperatures are in the 80's (Fahrenheit) throughout the year with the rains traditionally falling between November and April.
Bali is spared a monsoonal season and rains, when they do come, generally last only several hours, lowering the temperatures slightly and making for greener scenery all around.
High season is during the months of July and August. However best time to come to Bali is May, June and September, just before and just after high season. It's still dry season, it's less humid, and room prices can be 30-50% cheaper than during high season. Many shops offer sales and promotions, restaurants are less crowded in those mid-season months, and in general Bali is a bit more relaxed.
It's also the best time for water sport activities such as scuba diving, surfing, snorkeling, etc. Waters are clear, crowd not too bad etc. Also the other attractions such as the family parks and fun things to do (Bali Zoo, Bali Bird Park, Marine & Safari Park, Waterbom, White Water Rafting, Monkey Forest, etc) have less visitors which can make the experience far more enjoyable. And not to forget, in general the traffic and hustle bustle on the roads is more bearable. Especially in Kuta, Legian and sometimes even Seminyak the narrow streets are packed during certain times in the day with cars and motorcycles. Some tourists love it that way and could not imagine a holiday otherwise, but if you like it more quiet, then Kuta and Legian during high season might not the your best choice.
Balinese are generally modest in their modes of dress and believe that the most basic sign of respect to another is correct attire.
While shorts and singlets are generally acceptable while shopping or just walking, long trousers for men and dresses for women are strongly suggested when visiting friends, calling on government offices, or attending places of worship.
Specific rules apply whenever visiting a Balinese Pura or temple. Your Bali Discovery guide will make sure that guests are aware of the protocols and have a sarong available to wear whenever visiting a pura.
Although Indonesia is a Muslim country, Hinduism is the predominant religion in Bali. While the rules are relaxed for travelers in beach towns, when planning what to wear in Bali, please be respectful of the local culture.
Shorts are fine on the beach but trousers or skirts that fall below the knee are ideal when traveling to small towns or non-touristy destinations. Sleeveless tops are ok to wear juts carry a lightweight scarf that you can wrap around your shoulders if necessary or a lightweight long sleeve you can layer over if going to temples.
You may see locals wearing skinny jeans and long sleeve tees but you'll probably roast if you're not used to the weather – be prepared with lightweight fabrics that are great for both the heat and humidity.