Nunthaburi National Park covers the areas of Tha Wangpha District, Muang District, and Baan Luang District of Nan Province within an approximate area of 548,125 rai. The National Park consists of virgin forests and abundant natural resources, biological diversity. The National Park is the source of rivers and having prominent natural tourist attractions.
The geographical features of the National Park consist of high mountains, extending northwards. The National Park is situated in the western part of Nan Province until reaching the Lao People’s Democratic Republic. The site of the National Park is approximately 300-1,674 meters above the medium sea level. The average slope of the site is approximately 50%. Yod Doi Wao is the highest mountaintop of the National Park (at the height of 1,674 meters above the medium sea level).
The National Park has the tropical weather condition, influenced by the southwestern monsoon during the rainy season and the northeastern monsoon in winter. The weather at the National Park can be divided into 3 seasons including summer (March-May), rainy season (June-October), and winter (November-February). The minimum average temperature is approximately 8.4°C and the maximum is 40.8°C. The average rainfall is approximately 1,197.6 mm/year.
Major plants in the mixed deciduous forests include teak, Leguminosae (Pradoo), Xylia Xylocarpa (redwood plants), Lagerstroemia (Tabaek), Afzelia Bijuga (Maka), meanwhile, lower plants include different kinds of bamboo.
Major plants in the arid, evergreen forests include Dipterocarpus Alatus (Yang Khao), Dipterocarpus Costatus (Yang Daeng), Malabar Ironwood, Indian Mahogany, Michelia Alba, Mangifera Caloneura Kurz (wild mango), meanwhile, lower plants include different kinds of bamboo, Calamus Caesius, palms, ferns, Caryota urens, etc.
Major plants in the virgin forests include different kinds of Lithocarpus Cantleyanus (Kor), Betula Alnoides Buchham (Kamlang Suerkrong), Podocarpus Wallichianus (Payamai), Benzoin, Cinnamon, Eaglewood, meanwhile, lower plants include different kinds of moss and ferns.