The annual rainfall in the South Western Ghats montane rain forests in India exceeds 2,800 mm. The rainfall is caused by the northeast monsoon during the months of October to November and the southwest monsoon causes rainfall in the forests during the months of June to September. The forests are also considered as the wettest portion of peninsular India. The forests are home to a rich variety of plant species, because of having a cool and moist climate, high rainfall, and variety of microclimates brought about by differences in elevation and exposure. About 35% of the plant species are endemic to the ecoregion and the forests support a great diversity of species. The trees in these forests generally form a canopy at 15 to 20 m, and the multistoried forests are rich in epiphytes, especially orchids.
The majority of the fifty endemic plant genera found in the South Western Ghats montane rain forests in India, are monotypic. The characteristic canopy trees found in these forests include Cullenia exarillata, Mesua ferrea, Palaquium ellipticum, Gluta travancorica, and Nageia wallichiana. The other important evergreen tree species found in the forests include the Calophyllum austroindicum, Garcinia rubro-echinata, Garcinia travancorica, Diospyros barberi, Memecylon subramanii, Memecylon gracile, Goniothalamus rhyncantherus, and Vernonia travancorica, etc. There are also several other plant species found in the forests including the Pygeum gardneri, Schefflera racemosa, Linociera ramiflora, Syzygium spp., Rhododendron nilgiricum, Mahonia nepalensis, Elaeocarpus recurvatus, Ilex denticulata, Michelia nilagirica, Actinodaphne bourdellonii, and Litsea wightiana, etc.
The South Western Ghats montane rain forests in India are home to a rich variety of fauna species and the forests are high in endemism, as well. The forests harbour almost 20 percent of India's mammal fauna and a total of 78 mammal species can be found in the forests. Out of them, 10 are considered as endemic. These endemic species are Suncus montanus, Latidens salimalii, Trachypithecus johnii, Viverra civettina, Paradoxurus jerdoni, Hemitragus hylocrius, Funambulus layardi, Funambulus sublineatus, Mus famulus and Vandeleuria nilagirica. About 42% of fishes, 48% of reptiles, and 75% of amphibians are the found in these forests. The largest Elephant populations in India are found in these forests and other important fauna species include the threatened species like Tiger, Leopard, Sloth Bear, Gaur, and Wild Dog. The rare and endemic species Nilgiri Tahr and the endangered endemic primate species like Lion-Tailed Macaque and Nilgiri Macaque are also found in the forests.
The South Western Ghats montane rain forests in India provide habitat to a rich variety of bird species. The total number of bird species found in the forests is 309, out of which, 10 are considered as near-endemics and three are strict endemics. These near-endemic and strictly endemic species include the Nilgiri Wood-Pigeon, Malabar Grey Hornbill, White-Bellied Treepie, White-Bellied Shortwing, Grey-Headed Bulbul, Grey-Breasted Laughingthrush, Rufous Babbler, Black-and-Rufous Flycatcher, Nilgiri Flycatcher, Broad-Tailed Grassbird, Nilgiri Laughingthrush, Nilgiri Pipit, and Malabar Parakeet. The forests are also home to about 90 of India's 484 reptile species that are endemic to them. These species include eight endemic genera like the Brachyophidium, Dravidogecko, Melanophidium, Plectrurus, Ristella, Salea, Teretrurus, and Xylophis. The amphibian fauna in the forests exhibits even greater levels of endemism, as almost 50 percent of India's 206 amphibian species are endemic to this ecoregion. The species include six endemic genera like the Indotyphlus, Melanobatrachus, Nannobatrachus, Nyctibatrachus, Ranixalus, and Uraeotyphlus.