What to expect in Seoul in September
September is a strong choice for Seoul: 26° / 15°, with manageable crowds at the big attractions and prices close to the yearly average.
Seoul weather in September
Typical conditions in Seoul during September, based on long-run climate normals rather than any single year. Treat it as a planning guide, not a forecast.
| Average high | 26°C 79°F |
|---|---|
| Average low | 15°C 59°F |
| Rainfall | Moderate 40/100 |
| How it feels | Warm and comfortable |
Average highs sit around 26°C with lows near 15°C. Rainfall is moderate; the odd shower is likely.
Crowds & demand
Crowd levels are Moderate for Seoul — manageable crowds at the big attractions.
Prices & value
Prices run mid-range this month: prices close to the yearly average.
What to pack
Light layers for 26°C days and something with sleeves for evenings, which cool to around 15°C.
What it costs
Costs in September sit around the yearly average for Seoul — neither a bargain nor a squeeze. Booking a few weeks out is usually enough. Compared with the most expensive month of the year, you are looking at roughly 31% less.
Who this month suits
- Travellers who want the most reliable weather
- Anyone travelling on a budget
- Visitors who want to catch a festival
Events & what’s on
Look out for Chuseok Harvest Festival while you’re there.
- Chuseok Harvest Festival — Korea's lunar harvest holiday empties the city as families travel to ancestral hometowns.
Seoul in September compared with nearby months
If your dates are flexible by a few weeks, this is what shifting them actually buys you.
| Month | Temp | Crowds | Price | Score |
|---|---|---|---|---|
| July | 29° / 22° | Low | $ | 64 |
| August | 31° / 23° | Low | $ | 62 |
| September · This month | 26° / 15° | Moderate | $$ | 62 |
| October | 19° / 8° | High | $$$ | 48 |
| November | 11° / 1° | Moderate | $$ | 49 |
These months score higher for Seoul on the same blend of weather, crowds and price. Same destination, better odds.
Or go somewhere else in September
If the destination is negotiable but the month is not, these places are at their best in September.
Figures are climate normals and modelled estimates — a planning guide, not a forecast. We separate fact, estimate and recommendation. Updated August 2026
