South Korea
Seoul in September
In September, Seoul averages a daytime high of 26 °C and a night-time low of 16 °C, with about 154 mm of rain over the month. It falls outside Seoul's most comfortable months, October.
- Average high
- 26 °C
- Average low
- 16 °C
- Rain in the month
- 154 mm
- Daylight on 15 Sep
- 12 h 20 min
- Comfortable month
- No
- Places to stay
- 292
When to go
How September compares with the rest of the year in Seoul
September is the 4th warmest month in Seoul by average daytime high; across the year the highs run from 2 °C to 30 °C and the lows from -7 °C to 22 °C. By day, September is 4 °C cooler than August, and October is 6 °C cooler than September.
September brings 154 mm of rain, more than the monthly average of 112 mm (1343 mm a year); it is the 3rd wettest month.
On 15 September the sun is up for about 12 h 20 min, against 9 h 30 min at the shortest and 14 h 40 min at the longest point of the year (calculated from the latitude, sunrise to sunset).
| Month | High | Low | Rain | Comfortable |
|---|---|---|---|---|
| January | 2 °C | -7 °C | 15 mm | |
| February | 4 °C | -5 °C | 24 mm | |
| March | 11 °C | 0 °C | 35 mm | |
| April | 18 °C | 6 °C | 83 mm | |
| May | 23 °C | 12 °C | 105 mm | |
| June | 27 °C | 17 °C | 134 mm | |
| July | 29 °C | 22 °C | 358 mm | |
| August | 30 °C | 22 °C | 320 mm | |
| September | 26 °C | 16 °C | 154 mm | |
| October | 20 °C | 10 °C | 47 mm | Yes |
| November | 12 °C | 2 °C | 48 mm | |
| December | 4 °C | -5 °C | 20 mm |
Comfortable means average daytime high between 18 °C and 29 °C and under 80 mm of rain in the month. Averages for 1991–2020 over the surrounding area, a grid square about 50 km across, so a coast or a nearby mountain can make the town itself warmer or cooler. Data: CRU TS v4.10, Climatic Research Unit, University of East Anglia (Open Database License).
When to go
Is September a good time to visit Seoul?
Not by the measure used here: about 154 mm of rain is 80 mm or more. The comfortable months in Seoul are October; the nearest is October.
The measure is about weather for a city stay only; it says nothing about events, school holidays or prices.
Public holidays in South Korea in September
Nationwide public holidays; shops and offices may close on these dates.
Where to stay
Where to stay in Seoul
This guide lists 292 places to stay in Seoul: 4 chain properties with their details and own websites, and 288 hotels recorded in Wikidata. By straight-line distance from the centre: under 1 km, 76; 1–3 km, 123; 3–10 km, 89.
Sources: climate from CRU TS v4.10 (Climatic Research Unit, University of East Anglia; Open Database License), 1991–2020 averages; day length calculated from the latitude; public holidays from python-holidays (MIT); places to stay from each operator's own public pages and Wikidata. How this guide is made.