Autumn colour develops across Korea over several weeks rather than on one fixed date. Mountain areas such as Seoraksan often change before lower and more southerly settings, while temperature, rain and wind affect the timing and strength of local displays.
The route is built around that variability. Seoul introduces autumn in palace gardens; Seoraksan expands it to mountain scale; Andong and Gyeongju place seasonal colour around lived and archaeological heritage. Busan provides a southern finish rather than a foliage guarantee, so each stop retains cultural value even if colour arrives earlier or later than expected.