Naejangsan National Park experiences the distinct 4 seasons and it is opened all year round for visitors. However, trekking is only possible during spring to autumn (not possible in winter). Weatherwise and for beautiful scenery, the best time to visit is during autumn (November being at peak season for colourful autumn foliage). Spring is also another good season, but it will get warm, humid and rainy during summer months.
There are several warning signboards in the national park and you need to take note of them. Some of them will warn you that certain paths should not be taken because they are not the official paths of the various trekking routes. Also, there are warning signs which tell you to protect the environment, not to litter and camping is only allowed in certain designated areas of the national park.
During trekking at Naejangsan National Park, it is very important to follow the marked trekking routes and you should get a map from the tourist information office before starting. There are signboards (see photos) at the junctions which will tell you the various destinations and distances. If you have problems, there are wooden position markers located along each path where you can contact the park authorities using the telephone numbers indicated on the markers (see photo).