Hot, tropical climate at sea level, cooling towards the highlands which also cause climatic variation from one area to another, affecting the southeast trade winds and the northwest monsoons. The majority of the rain falls between December and March due to the northwest monsoon, although Port Moresby enjoys a dry season at this time. There is frost and there are occasional snow falls on the highest mountain peaks.

Tropical, lightweights and cottons are recommended. In the highlands, warmer clothing is needed. Rainwear is advised for the monsoon season (December to March).