Is the weather good in South Korea in September 2025?
For the past few decades, the average daily temperatures in South Korea during September have been around +79°F.
In South Korea the temperature rarely varies more than seven degrees between the different parts with the highest temperature +79°F in Seoul to +77°F in Busan. So you should be able to pack for similar conditions wherever you go in the country.
Temperature, wind and humidity in September
- rainiest? Busan, with an average of 5 mm of rain and humidity of 77%;
- warmest? Seoul, with daytime temperatures averaging +79°F;
- windiest? Seoul, with an average of 2 m/s;
- coolest? Busan, with daytime temperatures averaging +77°F;
How good is the weather in South Korea in September?
How warm is it in South Korea during September?
This is how hot it usually is in September
- Average maximum temperature for the month: +77°F;
- Average minimum temperature for the month: +66°F;
- Highest monthly temperature: +81°F;
- Lowest monthly temperature: +61°F;
Monthly temperatures:
- Warmest: August with an average +84°F during the day;
- Coldest: January with an average +41°F of the day;
- Hottest month in hottest city: August in Seoul;
- Coldest month in coolest city: January in Busan;
Winds in South Korea during September
September tends to offer light winds averaging 2 m/s. However, coastal cities may experience breezes during the mornings and afternoons.
Comparison between cities in September:
- Highest average wind speed: Seoul with 2 m/s;
- Lowest average wind speed: Busan with 2 m/s;
- Windiest day of the month: Seoul with 2 m/s;
- The least windy day of the month: Busan with 2 m/s;
Humidity and precipitation in South Korea in September
Comparison between cities in September:
- Highest average rainfall: Busan with 165 mm;
- Lowest average rainfall: Seoul with 117 mm;
- Most number of rainy days: Busan with 14 rainy days;
- Least number of rainy days: Seoul with 10 rainy days;
- Highest risk of rain during the day: Busan with 47%;
- Least risk of rain during the day: Seoul with 33%;
- Highest average humidity: Busan with 77%;
- Lowest average humidity: Seoul with 72%;
Tips for traveling to South Korea in September
Looking for some tips for traveling to the sun, snow, or whatever you're aiming for South Korea? Activities, weather, and clothing are closely linked. In addition, it's important to pack only what you really need so you don't have to worry about heavy packing or paying extra baggage fees.
Here is some advice on what to pack and what kind of activities you can do in the South Korea based on the weather that September is expected to bring. The advice applies to the country as a whole – local weather and possible activities may differ somewhat.
Pack right for September
- Sunshine does give you a nice color and a boost of vitamin D. However, if you don't have a lot of skin pigment, you should sunbathe carefully to avoid burning yourself, getting sun rash and, in the worst case scenario, skin cancer. This is where sunscreens and opaque clothing work particularly well. Another safe way is to stay in the shade when the sun burns the most, roughly between 9 am and 3 pm.
- Cool weather is between warm and cold. This means you can bring long pants and/or a longer skirt and an extra sweater. Be aware that cool days can alternate with cold nights - it may be wise to also pack a hat, gloves and a scarf.
- Light winds are probably most comfortable in hot weather but is cooling in cool and cold weather. If it is hot (when the air temperature is about 30 degrees), the wind can have a warming effect. A thin, windproof jacket and long trousers help to counteract these effects.
- High humidity means that the air conducts heat to and from the skin more easily. For example, if the air is hot (above skin temperature), it will be harder to stay cool. On the other hand, if the air is cool or cold, it is more difficult to stay warm. In high humidity, the choice of clothing makes less of a difference. However, your physical activity plays a bigger role.
FAQ
What can you do outside when it's warm in South Korea?
Is September a good time to visit South Korea?
Monthly weather in South Korea
Source of the data
For this page, we’ve looked at the typical weather in South Korea, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.