Seoul Running Routes: Han River 100km, Bukhansan & 5 Loops

The cleanest, mildest running weather is late September through October (12-22°C, low humidity, low pollution) and April through early May (cherry blossoms but late-season yellow dust risk). Avoid July-August (monsoon: 414mm rain in July alone, 76% humidity, frequent thunderstorms) and mid-January through mid-February (below -3°C with dry cold). The Seoul Marathon (March) catches the tail of winter — 2-10°C race-day range and possible yellow dust. Check temperature, humidity and air on the day with our Weather Score Calculator.

The Han River path system runs 100+ km of paved, car-free paths on both banks — Yeouido, Banpo, Ttukseom, Jamsil all connect along a continuous network. Rest stations every 2 km offer free water fountains, public restrooms, and outdoor exercise equipment. Distance markers are painted on the path. Both banks are linked by pedestrian-accessible bridges, so 10-30 km loops are easy. It is completely free, well-lit until midnight, and safely runnable at all hours including pre-dawn.

Yes — Seoul is the rare megacity with serious mountains inside its limits. Bukhansan National Park (Baegundae peak 836m) is accessible by subway Line 4 in 30 minutes; trails range from gentle Bukhansan Dulle-gil (no scrambling) to scrambling-required summit pushes. Namsan (270m, 10 km of paved paths) sits in the city centre and pairs a 2 km steep climb with the N Seoul Tower at the top — popular for hill repeats. Inwangsan (Hanyangdoseong fortress trail) and Gwanaksan (629m, south side) round out the options. Trail shoes recommended for anything above Dulle-gil level.

The next race is March 21, 2027. International registration historically opens July 1 at 10:00 KST the year before, on a first-come-first-served basis (not lottery) — 20,000 marathon bibs sell out within minutes. Full marathon entry requires a sub-5:00 marathon, sub-2:12 half, or sub-1:00 10K certificate from a chip-timed race within the past 2 years, with your English (passport) name. The 10K race has no qualifying time. Apply at the official overseas registration page; see our Seoul Marathon course analysis for full strategy.

Yes — Seoul's crew culture is highly organized and English-friendly. Seoul Flyers (Tue/Wed/Thu/Sat/Sun, the largest and most foreigner-welcoming) and SRC Seoul (Tue/Thu, social-pace) both publish weekly schedules on Instagram and accept drop-ins. Eighty Eight Seoul Running Club meets Thursday and Sunday 9 pm. Meetups typically start at a Han River rest station or near Seongdong's Goodrunner specialty store. Etiquette note: no shirtless running (Yeouido has explicit signage), keep right on shared paths, and large noisy groups are discouraged outside organized events.