Erawan National Park is defined by tower karst and mountainous areas ranging in elevation from 165 to nearly 1,000 meters. The area is mostly karst topography, which rise vertically in the east and the west of the area, especially near Erawan Waterfall. There are also plains in the central region, which has a long mountain range. The mountain range runs from the northwest to the southeast and is composed of essential mountains, including Khao Nong Phuk, Khao Plai Dinsor, Khao Mo Thao, Khao Chong Pun, Khao Phurang Rin, and Khao Kro Krae.
      These mountains form the watershed of many important waterways. There are two sections: in the east, there is Monglai Creek, and Amatara Creek, which flow intoErawan Waterfall; in the north there is Sa Dae Creek and Nong Kop Creek., Sa Dae Creek flows into Sinakharin Dam. Nong Kop Creek is fed by Sai Yok Creek, which forms Sai Yok Waterfall. In the western and southern regions are Tap Sila Creek and Khao Phang Creek, known as the sources of beautiful waterfalls, "Khao Phang Waterfall" or "Sai Yok Noi Waterfall". 

The Erawan National Park's climate is classified into three seasons: 
- Rainy season, which lasts from May to October.
- Winter, which lasts from November to January.
- Summer, which runs from February to April.

        The southwest and northeast monsoons influence the Erawan National Park, bringing rain. However, the area's location is in a rain shadow, thus expecting less rainfall, and the weather is hotter than equivalent areas. As a result, traveling is not affected by rain and it possible to travel throughout the year.

Forest Features in Erawan National Park
        Mixed deciduous forest accounts for 81% of the National Park area, and it is located between elevations of 100 to 800 meters above sea level. Essential plants include Afzelia Wood, Anogeissus acuminata (Roxb. ex DC.) Guill. & Perr, Var. lanceolata C.B. Clarke, Indian laurel, Indo-Chinese Milla, Burma Padauk, Bauhinia malabarica Roxb, Cratoxylun maingayi Dyer, Hog Plum, Bungor, Moulmein Lancewood, Ebony Tree, and Java Plum. There are numerous varieties of bamboo scattered throughout the area or in clustered in specific locations, such as Bambusa bambos (L.) Voss, Thyrsostachys siamensis Gamble, Dendrocalamus membranaceus Munro, and Bambusa oliveriana. Additionally, there are ivy and lowland plants, such as Bauhinia, Rauwenhoffia siamensis (Scheff) Ban, Jackal Jujube, Harrisonia perforate (Blanco) Merr, Wild Sage, Wild Blackberry, Big Lygodium, Croton oblongifolius Roxb., Wild Ginger, Barleria strigosa Willd, and Crape Ginger. 

        Deciduous diptarocarp forests have a under 2 percent of the area and are scattered between elevations of 100 to 800 around the National Park Ranger Stations O Wo No. 8 (Lam Ton) and near Thung Na Dam. Plants include Damnoted Burma Sal, Burmese Sal, Jamba, Quercus kerrii Craib, Malacea Tree, Wodier Tree, Morinda coreia Buch.-Ham, Casearia grewiifolia Vent. var. grewiifolia, Holarrhena pubescens Wall. ex G. Don, Dalbergia lanceolaria L.f. var. lakhonensis (Gagnep.) Niyomtham, Great Elephant Apple, and Heliciopsis terminalis Sleum,.
        Dry evergreen forest accounts for 14.35% of the area and are commonly found on long ridges near the center of the national park at lower elevations of  between 600 and 800 meters above sea level, located along the moist plains by the rivers. Plant species found include Polyalthia viridis Craib, Bo Tree, Almond-Wood, Iron Wood, Bastard poon, Garuga pinnata Roxb, Devil Tree, Carallia brachiata (Lour.) Merr, Ivru Wood, Memecylon caeruleum Jack, Streblus ilicfolius, and Syzygium siamense. The lower ground plants include Calamus viminalis Willd, Bauhinia scandens var. horsfieldi, Siamese white ixora, Jasminum elongatum (Bergius) Willd, Spider Plant, Cnesmone javanica Blume, Cinnamon, Thorn Bamboo, and Disporum calcaratum D.Don. 

      The survery showed that mammals, reptiles, amphibians, birds, and other aquatic animals, including a diverse array of fish were included in the National Park. The most important and common wildlife are Asian Elephant, Asiatic Black Bear, Serow, Barking Deer, Sambar Deer, Wild Boars, Common Gibbon, Phayre's Leaf-Monkey, Pig-Tailed Macaque, Bengal Slow Loris, Leopard Cat, Common Palm Civet, Chipmunk, and Black Baza. There are also many birds such as Gray-Backed Pheasant, Kalij Pheasant, White-Breasted Waterhen, Common Sandpiper, Eastern Spotted Dove, Greater Coucal, Indian Roller, Grey-Capped Pygmy Woodpecker, Streak-Eared Bulbul, Pellorneum ruficeps, as well as reptiles and amphibians, such as King Cobra, Banded Krait, Burmese Python, Indo-Chinese Rat Snake, Blue Crested Lizard, Many-Lined Sun Skink, Southeast Asian Softshell Turtle, Asian Common Toad, Puddle Frog, Hill Forest Frog, Tree Frog, Phlogacanthus pulcherrimus T.Anderson, Greater Brook Carp, Striped Tiger Nandid, Java Barb, Eye-Spot Barb, Waterfall Crabs, Crabs of Tenasserim, and Kanchanaburi Crabs.