One Day It Was Summer. Now Seoul Feels Like Fall.

Just a few days ago, Seoul still felt like summer.

People were wearing short sleeves. Air conditioners were still running. Cold drinks were still very much part of the daily routine.

And then, almost suddenly, the air changed.

On September 10, Seoul woke up to temperatures around 61°F (16°C). The morning air felt noticeably cool, especially after weeks of summer heat.

By the afternoon, temperatures were expected to climb to around 77–79°F (25–26°C).

Summer did not exactly disappear overnight.

But Seoul suddenly started feeling like fall.

From Summer Heat to Cool Mornings

The change was not imaginary.

On the morning of September 10, temperatures in Seoul dropped to around 61°F (16°C), several degrees cooler than the previous morning. By afternoon, temperatures were expected to rise to around 77°F (25°C).

That means the same day can feel completely different depending on the time.

A light jacket may feel necessary when you leave home in the morning.

By lunchtime, you may wonder why you brought it.

And by evening, you may want it again.

This wide temperature swing between morning and afternoon is one of the first signs that Seoul is moving into autumn.

So, What Happened?

The reason is a change in the air moving into the Korean Peninsula.

Cooler, drier air is moving down from the north, replacing some of the hot, humid air that dominated the summer.

That is exactly what the weather map on Korean television has been showing.

The blue arrows spreading across the map tell a simple story: cooler air is moving south.

And suddenly, Seoul feels different.

This is one of those moments when a weather forecast becomes more than a forecast.

You can actually feel the change when you step outside.

Seoul's September Weather Can Be Confusing

For visitors to Seoul, September can be a surprisingly confusing month.

The calendar says autumn.

The weather does not always agree.

Early September can still feel very much like summer, with temperatures reaching around 86°F (30°C).

Then cooler air arrives, and the morning can suddenly feel almost autumnal.

This is why packing for Seoul in September can be tricky.

You might need a T-shirt in the afternoon and a light jacket in the morning.

You might still want iced coffee at lunchtime but find yourself looking for something warm after sunset.

And you may see people wearing completely different kinds of clothes on the same subway train.

Some are still dressed for summer.

Others have already switched to fall.

**Nobody is necessarily wrong.

That's just September in Seoul.**

The Strange Moment When Seoul Changes Seasons

There is also a very Korean feeling to this transition.

People do not necessarily announce, "Autumn has arrived."

Instead, you start noticing small things.

The air feels less heavy.

The mornings become quieter and cooler.

The sunlight feels slightly different.

You stop sweating the moment you walk outside.

You begin to think about long sleeves.

And then one morning, you realize:

Maybe summer is actually over.

The trees may still be green.

The temperatures may still rise into the upper 70s°F.

But something has changed.

Summer Isn't Completely Gone

Of course, it would be too early to put away all your summer clothes.

Seoul is not suddenly cold.

Afternoon temperatures are still expected to reach the upper 70s°F over the next few days.

So this is not the beginning of winter.

It is something much more subtle.

It is the beginning of the transition.

Summer is still here.

Fall is simply beginning to take its place.

And that is what makes this time of year interesting in Seoul.

The Best Part of Seoul's Fall May Be This Moment

For many people, autumn is their favorite season in Seoul.

But before the leaves turn red and yellow, there is this short period when the city is caught between two seasons.

The afternoons still belong to summer.

The mornings are starting to belong to fall.

Cafés still serve plenty of iced drinks.

But people are beginning to think about hot coffee.

Air conditioners are still running.

But windows can finally be opened.

It is a small change, but after a long Korean summer, it feels surprisingly significant.

So if you are in Seoul right now, pay attention the next time you step outside in the morning.

You may notice it before you see it.

The air is different.

The light is different.

And after months of heat and humidity, Seoul is finally beginning to breathe again.

**One day it was summer.

Now Seoul feels like fall.**

Source: Korea Meteorological Administration (KMA) and MBC News Weather