The main variable of Papua New Guinea΄s climate is not temperature or air pressure, but rainfall. Papua New Guineas climate can be described as tropical climate, with the coastal plains averaging a Temperature of 28°C, the inland and mountain areas averaging 26°C, and the higher mountain regions, 23°C. The area's relative humidity is quite high, and ranges between 70 and 90 percent.
The extreme variations in rainfall are linked with the monsoons. Generally speaking, there is a dry season (June to September), and a rainy season (December to March). Western and northern parts of Papua New Guinea experience the most precipitation, since the north- and westward-moving monsoon clouds are heavy with moisture by the time they reach these more distant regions.
Typhoons can hit Papua New Guinea from December to mid March, and can sometimes cause heavy damage, flooding and erosion.
Lightweight cotton clothing is advised throughout the year, with an umbrella or raincoat for sudden tropical cloudbursts. A sweater is needed in the mountainous inland areas. No matter where you go, be prepared for high temperatures and humidity.
The Climate of Papua New Guinea can be classified as Af climate, a hot, humid tropical climate with all months above 18°C.