How does the experience change across seasons?

Korea is a hiker's paradise and the seasons genuinely change the experience. Spring, around April and May, is gorgeous with cherry blossoms and azaleas and mild temperatures, though trails get busy on weekends and there can be fine-dust days, so check the air quality before heading out. Summer, June through August, is hot and very humid and overlaps the monsoon (장마) around July with heavy rain, so start early, carry plenty of water, watch for slippery rocks and flash floods, and expect some trails to close after storms, while higher mountains like Seoraksan stay a bit cooler.

Autumn, late September through November, is widely considered the best time, with spectacular foliage and crisp clear air, and it is peak season so famous peaks like Seoraksan, Naejangsan, and Bukhansan get crowded at the height of the colors. Winter, December through February, is cold but beautiful with snow-covered ridgelines, and it needs real preparation: crampons (아이젠) for icy trails, proper layers, and an early start since daylight is short, with some high or exposed routes closed for safety. Year round, Korean trails are well marked with shelters and clear signage, the Korea National Park app and Naver Map help with routes, and a rule locals follow is to pack a windproof layer in any season, since ridgetops are far colder and windier than the trailhead. Whatever the time of year, good shoes, water, and an early start will serve you well.