Cities in INDONESIA
With the exception of the highlands, most of Indonesia has a very humid (often above 90%) tropical rainy climate, with average monthly temperatures differing little from the high annual average, which is around 25 to 27 °C. The maximum temperature can reach a value of 36 °C.
The temperature in the mountains decreases by about 1 °C per 170 meters ascent. In the central mountains of New Guinea, perpetual snow occurs on the peaks above about 4500 meters and the mercury can drop below freezing point. Parts of Java, Bali, Nusa Tenggara, Sulawesi, the Moluccas and Irian Jaya have a savannah climate with a short dry season. The Palu Valley of Central Sulawesi falls below 500 mm annually, making it the driest area in the archipelago. On the more southeastern islands of Timor and Roti, the dry season can last up to seven months.
There are large differences in terms of precipitation, both in terms of quantity and the season in which it falls. From December to the end of March, prevailing winds from the northeast come over North Sumatra, Kalimantan and Sulawesi, but as they cross the equator they deflect and become above Java, Nusa Tenggara and beyond west-northwest. From June to October, the direction is the other way around, with an exceptionally dry air stream from the Australian desert passing the southern half of Indonesia and changing from a southeast to a southwest direction over Sumatra.
Then this air flow has absorbed a lot of water vapor. Precipitation is not evenly distributed throughout the year. There are dry and wet months. The number of dry months generally increases from west to east and from north to south. A dry month is said to have less than 60 mm of rainfall. However, in areas that are highly exposed to the monsoons, much heavier rainfall occurs. In Padang, for example, on the southwestern slopes of Sumatra, falls about 4500 mm annually. Average annual rainfall is between 2000 and 3000 mm, in Jakarta 1800 mm.
In general, it can be said that October to May in Indonesia is the wet monsoon season ("musim hujan"). In the afternoon it often rains very locally for a few hours, which refreshes everything and the temperature drops slightly. Most rain falls in January and February.
The dry season ("musim kemarau"), from May to October, is the most favorable for traveling. It is then very hot, and there is only an occasional shower that refreshes nature.
The very global table below provides a good picture
Dalton, B. / De Indonesië reisgids
Darmawie-van Oijen, J. / Indonesië : handboek voor reizigers
Homburg, E. / Indonesië
Lyle, G. / Indonesia
Martyr, D. / Indonesië
Mastenbroek, B. / Kijk op Indonesië
Muller, K. / Indonesië : het 13.000 eilandenrijk
Oosterman, I. / Indonesië
Schulte Nordholt, N. / Indonesië : mensen, politiek, economie, cultuur
Te gast in Indonesië
Wassing, R. S. / Indonesië : Java, Bali, Lombok, Sumbawa, Komodo, Flores, Sumba, Timor, Sumatra, Zuid- en Oost-Kalimantan, Sulawesi, Singapore
Witjes, B. / Indonesië
Copyright: Team Landenweb