Complex mountainous of Tanonthongchai hill range that is lying along north-south line. 400-1,909 m high above msl, Doiphatang is the highest mountain, moreover there are the others mountain which fall down high and they are the main sources of 3 streamlines as Nammaejam, Nammaewang and Nammaeteun that tributary to Maenamping.
From the influent of southwest monsoon wind that brings moisture and rainy cloud so it causes of the season. Summer runs in March to May, rainy runs in June to November and cold season runs in December to February. Average temperature all year long is 20 c, dropping at 10-14 c. average rain amount is 2,000-2,100 ml/year.
There are 4 of forest types in Mae Wang National Park,
Mixed deciduous forest found in the range of 400-1,000 m above msl.
Dry dipterocarp forest found in the range of 400-900 m above msl along a crest and foothills that arid.
Pine hill forest found in the range of 900-1,500 m above msl.
Hill evergreen forest found this forest from 1,000 m high up.