Photo by Eunmi Park via Wikimedia Commons, CC BY-SA 4.0
South Korea › Seoul › Races
Seoul Marathon
Marathon, 10K in Seoul, normally held in March. A flat marathon course — Gwanghwamun start, finishing in the Jamsil Olympic Stadium; very fast.
The Seoul Marathon at a glance
| Distances | Marathon, 10K |
|---|---|
| Main distance | 42.2 km (marathon) |
| Usually held | March |
| Course | Flat |
| City | Seoul, South Korea |
| Typical conditions | 11.5°C high / 0°C low, rain on ~19% of days |
Gwanghwamun start, finishing in the Jamsil Olympic Stadium; very fast.
Entering the Seoul Marathon
Entry fees, closing dates and start times are set by the organiser and change every year, so they are not reproduced here — a stale deadline is worse than none. The organiser’s own site and its social channels are the authoritative source for the current year, and are where entry opens.
What is stable, and what this page covers: the month the race is held, what the course is like, the conditions you should expect, and how long a build-up the distance needs.
Weather at previous Seoul Marathon races
Across the last ten years, Seoul in March has averaged a daily high of 11.5°C and a low of 0°C, with at least a millimetre of rain on about 19% of days.
These are recorded observations for the race month averaged over ten years, not a forecast and not a single past race day — race dates move, so one day’s figures would mislead. Source: Open-Meteo historical archive.
How to prepare for the Seoul Marathon
How long to train
Build for 16 to 20 weeks from a base you already hold rather than from nothing. For marathon the block should peak at a longest run of 30–32 km, reached at least two weeks before race day so there is time to taper. Three weeks of taper is standard: cut volume by roughly a third each week while keeping some race-pace work so the legs stay sharp.
Training for this course
The course is flat, which means no downhill sections to give your legs a break — you hold one rhythm the whole way. Train on similarly flat ground so the repetitive loading is not a surprise, and practise holding goal pace for long stretches rather than surging.
Conditions in March
Conditions are usually good for racing: highs average 11.5°C and lows 0°C in March, which is close to ideal for marathon running. Dress for the temperature about ten degrees warmer than it actually is, since you will warm up within two kilometres.
Fuelling
Over 42 km you will need 30–60 g of carbohydrate an hour from early on, not once you feel empty. Rehearse the exact products in training — the gut trains like anything else — and check in advance which brand is handed out on course, because switching to an unfamiliar one mid-race is a common and avoidable mistake.
Race week
Sleep matters most two nights before, not the night before, so protect that one. Keep eating normally with a modest tilt toward carbohydrate, lay out kit the night before, and do nothing new: no new shoes, no new breakfast, no new socks. Plan to arrive at the start with time to spare — marathon fields move slowly through bag drop and security.
Distances and where the race is run
- Marathon — 42.2 km
- 10K — 10 km
The pin marks Seoul city centre, the area the Seoul Marathon starts and finishes in. This is not the course line: the route is set by the organiser and changes between editions, so the official course map for the current year is theirs to publish. The routes below are for training on the same roads.
Train on these roads: 10K routes in Seoul · long runs in Seoul · GPS art routes
Other races in Seoul
- JTBC Seoul Marathon — Marathon, Half marathon, November