The tropical climate has high annual temperatures and humidity. The lowlands are very humid year-round. Cooler temperatures prevail with the rise in altitude. The rainy season lasts from January to April. The southern swamplands are one of the wettest places on Earth.
Mangrove swamps abound along the coasts.
Forests, covering almost three fourths of the island area, consist of several kinds of palm, bamboo, oak, beech, and pine trees. Orchids and figs grow wild. New Guinea has nearly 500 species of birds. Colorful tropical birds include the bird of paradise, parrot, cockatoo, and flightless cassowary. Wildlife includes the tree kangaroo, wallaby, ring-tailed opossum, and bandicoot.