Lying along the equator, Indonesia has a tropical climate, with two distinct monsoonal wet and dry seasons. Average annual rainfall in the lowlands varies from 1,780–3,175 millimeters (70–125 in), and up to 6,100 millimeters (240 in) in mountainous regions. Mountainous areas—particularly in the west coast of Sumatra, West Java, Kalimantan, Sulawesi, and Papua—receive the highest rainfall. Humidity is generally high, averaging about 80%. Temperatures vary little throughout the year; the average daily temperature range of Jakarta is 26–30 °C (79–86 °F).
The nation of Indonesia is almost unimaginably vast: More than 17,000 islands providing 108,000 kilometers of beaches. The distance between Aceh in the West and Papua in the East is more than 4,000 kilometers (2500 miles), comparable to the distance between New York City and San Francisco. Laying on the western rim of the Ring of Fire Indonesia has more than 400 volcanoes, of which 130 are considered active, as well as many undersea volcanoes. The island of New Guinea (on which the Indonesian province of Papua is located) is the second largest island in the world. Provinces are usually grouped around larger islands and include smaller surrounding islands. The listing below follows this practice, except with Bali which is treated as a separate region in here.
| Sumatra (incl. the Riau Islands and Bangka-Belitung) Wild and rugged, the 6th largest island in the world has a great natural and cultural wealth with more than 40 million inhabitants. Habitat to many endangered species. |
| Kalimantan (Borneo) The vast majority of this, the world's third largest island, is covered by the Indonesian province. Uncharted jungles, mighty rivers, home of the orangutan, a paradise for the adventurer. |
| Java (and Madura) The country's heartland, big cities including the capital Jakarta, and a lot of people packed on a not-so-big island. Also features the cultural treasures of Yogyakarta, Borobudur and Prambanan. |
| Bali By far the most popular visitor destination in Indonesia, Bali's blend of unique culture, legendary beaches, spectacular highland regions and unique underwater life make it a perennial favourite amongst global travellers. |
| Sulawesi (Celebes) Strangely shaped, this island houses a diversity of societies and some spectacular scenery, Toraja culture, rich flora and fauna, world class diving sites. |
| Nusa Tenggara (Lombok including the Gili Islands, Sumbawa, Flores, Komodo and West Timor) Also known as the Lesser Sunda Islands, the "Southeast Islands", contain scores of ethnic groups, languages and religions, as well as Komodo lizards and more spectacular diving. |
| Maluku (Moluccas) The historic Spice Islands, fought over to this day, largely unexplored and almost unknown to the outside world. |
| Papua (Irian Jaya) The western half of the island of New Guinea, with mountains, forests, swamps, an almost impenetrable wilderness in one of the remotest places on earth. |
These visas can be obtained from the following airports on arrival: 
Effective February 1, 2004, Indonesia has introduced wide ranging changes in the national visa-free and visa on arrival system. We've tried to summarize those changes here for your convenience.
The Immigration Department has issued the long-awaited revisions to regulations that allow the granting of temporary stay permits for those over 55 years of age. This facility to provide renewable stay permits of one year's duration was originally announced in 1998 (Keputusan Menteri Kehakiman No. M.04-IZ.01.02 tahun 1998). In the first few years after the regulations were issued few retirees were actually able to actually get the visa due to the strict requirements. Revisions to the regulations in April 2002 (decree by the General Director of Immigration in law No. F. 492-UM.01.10, April 18, 2002) brought the requirements within closer reach of the financial capabilities of most retirees.
