Batam is only about 120 kilometers from the equator and is therefore warm throughout the year.
But, surprisingly, being a small island surrounded by sea means that usually it is neither oppressively humid nor hot. Average daily temperatures range from a minimum of 25 degrees to a maximum of 34 degrees Celsius (77 to 95 Fahrenheit) and humidity ranges from around 65 percent to 96 percent.
Hotels, bars, restaurants, shops and offices and most cars and taxis have air-conditioning.
Balmy tropical evenings
Visitors from temperate climes are likely to feel some discomfort if outside in the sun during the couple of hours of early afternoon and may find the days are hot in the months of May and June. Most visitors simply turn on the air conditioner, but the balmy tropical evenings are wonderfully inviting for outdoor dining and socializing.
Being near the equator also means that Batam is NOT subject to tropical hurricanes/typhoons and that the wet and dry seasons are not as well defined as in other regions. The annual average rainfall is 2,600 millimeters (about 105 inches).
Like Singapore, Batam is not within an active earthquake zone and was unaffected by the 2004 Asian earthquake/tsunami or the subsequent quakes that struck northwest Sumatra.