Air quality in Sejong

Air quality index (AQI) and PM2.5 air pollution in Sejong

Last update at (local time)

25.7K people follow this city

  • The profile image of follower
  • The profile image of follower
  • The profile image of follower
  • The profile image of follower
  • The profile image of follower
IQAir map with AQI colorful pins

Air Quality Data contributor(s)

Station(s) operated by

*IQAir’s AQI data modeled using satellite data. Learn more

Sejong does not have air monitor data

Be the first to measure and contribute air quality data to your community.

Become a contributor
Find out more about contributors and data sources


What is the current weather in Sejong?

Weather icon
WeatherBroken clouds
Wind1.3 mp/h
Pressure30.1 Hg

live aqi city ranking

Real-time South Korea city ranking

#cityUS AQI
1 Pyeongtaek, Gyeonggi-do


2 Boryeong, Chungcheongnam-do


3 Yeongi, Chungcheongnam-do


4 Osan, Gyeonggi-do


5 Seosan, Chungcheongnam-do


6 Taesal-li, Chungcheongnam-do


7 Dangjin, Chungcheongnam-do


8 Gaigeturi, Jeju-do


9 Jeju, Jeju-do


10 Anseong, Gyeonggi-do


(local time)


live Sejong aqi ranking

Real-time Sejong air quality ranking



live AQI index

Human face indicating AQI level


What is the current air quality in Sejong?

Air pollution levelAir quality indexMain pollutant
Good 42* US AQIPM2.5



PM2.5 concentration in Sejong is currently 2 times the WHO annual air quality guideline value

Health Recommendations

How to protect from air pollution in Sejong?

An open window iconOpen your windows to bring clean, fresh air indoors
A man cycling iconEnjoy outdoor activities


Sejong air quality index (AQI) forecast

DayPollution levelWeatherTemperatureWind

Good 42 US AQI

Human face indicating AQI level
Weather icon51.8°33.8°
Wind rotating 54 degree

2.2 mp/h

Monday, Nov 28

Good 43 US AQI

Human face indicating AQI level
Weather icon60.8°41°
Wind rotating 177 degree

6.7 mp/h

Tuesday, Nov 29

Good 38 US AQI

Human face indicating AQI level
Weather icon55.4°30.2°
Wind rotating 324 degree

15.7 mp/h

Wednesday, Nov 30

Good 33 US AQI

Human face indicating AQI level
Weather icon28.4°21.2°
Wind rotating 336 degree

13.4 mp/h

Thursday, Dec 1

Good 41 US AQI

Human face indicating AQI level
Weather icon30.2°21.2°
Wind rotating 344 degree

6.7 mp/h

Friday, Dec 2

Good 50 US AQI

Human face indicating AQI level
Weather icon35.6°24.8°
Wind rotating 135 degree

2.2 mp/h

Saturday, Dec 3

Moderate 61 US AQI

Human face indicating AQI level
Weather icon42.8°28.4°
Wind rotating 202 degree

11.2 mp/h

Interested in hourly forecast? Get the app


Historic air quality graph for Sejong

How to best protect from air pollution?

Reduce your air pollution exposure in Sejong


What is the current level of air pollution in Sejong?

Sejong, officially the Sejong Special Self-Governing City is a special self-governing city and de facto administrative capital of South Korea. It was conceived in 2007 as the new capital of South Korea to ease congestion in South Korea's current capital and largest city, Seoul, and hopefully encourage investment in the country's central region. Since 2012, the government has relocated many agencies and ministries to Sejong. According to a census conducted in 2020, Sejong had an estimated population of approximately 351,000 people. Despite the fact that the city is still under construction, it is expected to be home to 500,000 people by 2030.

Towards the end of 2021, Sejong was experiencing a period of “Moderate” air quality with a US AQI reading of 61. This United States Air Quality Index number is calculated using the levels of six of the most commonly occurring air pollutants, such as nitrogen dioxide, sulphur dioxide, ozone, carbon monoxide and both sizes of particulate matter, which are PM2.5 and PM10. It can then be used as the metric when comparing air quality in other cities around the world. If data is unavailable for all 6 pollutants, a figure can still be calculated by using what figures there are. The pollutants recorded in Sejong were; PM2.5 - 17 µg/m³, PM10 - 28 µg/m³, nitrogen dioxide (NO2) - 50.8 µg/m³ and carbon monoxide (CO) - 515.3 µg/m³.

This level of PM2.5 is almost twice the recommended safe level of 10 µg/m³ as suggested by the World Health Organisation (WHO) as being an acceptable level. Although no amount of air pollution is considered to be safe.

Does the level of air pollution remain the same throughout the year in Sejong?

Air quality is very volatile as it is subject to many external influencing factors such as meteorological and atmospheric changes.

Looking at the figures for 2020, released by it can readily be seen that the month that produced the best air quality was September when a “Good” figure of 11.5 µg/m³ was recorded. For the remaining eleven months of the year the level was classified as being “Moderate” with figures between 12.1 and 35.4 µg/m³. The month with the best air quality out of these was July with a figure of 12.2 µg/m³. The worst was January with a figure of 32.7 µg/m³.

Historically, records have been held since 2017 when a figure of 19.2 µg/m³ was recorded. A decline was seen the following year with a 21.9 µg/m³ reading. Another more noticeable decline was seen the year after when a reading of 26.5 µg/m³ was reported. However, by 2020, the level had reduced to 21.6 µg/m³. But this reading may have been affected by the COVID-19 situation as many vehicles were no longer in daily use because the offices were closed, in an attempt to halt the spread of the virus. Many factories and non-essential production units were also required to close which removed their emissions from the atmosphere.

Is there a main source of air pollution in Sejong?

In South Korea, fossil fuel combustion is the biggest cause of air pollution. Korea has few fossil fuel resources and imports everything but 1 per cent of its coal supply. Korea relies heavily on fossil energy for its economic growth and energy resource needs. Oil accounts for 38 per cent of primary energy supply, coal accounts for 29 per cent, and gas accounts for 15 per cent.

Transportation, factories and power plants all contribute to pollution. Conventional power plants burn fossil fuels to produce energy and release hazardous gases such as oxides and nitrogen, carbon monoxide, particulates and hydrocarbons into the atmosphere.

There are more and more cars on the road. In a fast-growing economy like South Korea, growth in imports and exports could increase fossil fuel burning. Increasing pollution, especially in large cities like Sejong, will cause more problems for residents.

Every spring, South Korea falls victim to huge dust storms. Dust storms occur in the dry desert areas of western China and Inner Mongolia. The effects of the Asian dust storm include respiratory diseases, cardiovascular diseases, obstruction of vision and product damage.

What can be done to reduce air pollution in Sejong?

The long-term solution is to buy an expensive air purifier for your home or car. Citizens are demanding government subsidies for such expensive products, especially for middle-class families.

The concentration of fine dust in the atmosphere is emitted in gaseous form such as fine dust (primary fine dust) directly emitted from emission sources, nitrogen oxides (NOx), sulphur oxides (SOx), ammonia (NH3), and volatile organic compounds (VOCs). It is a combination of fine dust (secondary fine dust) generated through reaction with other pollutants in the atmosphere. Therefore, in order to reduce fine dust, the emission of pollutants such as nitrogen oxide, which is the cause of primary and secondary fine dust, must be reduced together.

What are the health impacts of breathing dirty air in Sejong?

Outdoor ambient air pollution is a broader term used to describe air pollution in outdoor environments. Poor outdoor ambient air quality occurs when pollutants reach concentrations high enough to adversely affect human health and / or the environment. Outdoor urban air pollution is a more specific term that refers to outdoor ambient air pollution in urban areas, usually in or around cities.

Pollution is associated with increasing disease and mortality in South Korea. For example, exposure to sulphur dioxide causes chronic lung disease and respiratory disease. Exposure to ozone and particulate matter has been associated with respiratory and circulatory diseases and increased mortality. According to the Korea Environmental Research Institute, the dust kills 165 South Korean civilians annually and makes 1.8 million sick, including the elderly and those with respiratory problems.

Air pollution is a growing global health concern estimated to contribute to as many as 4.2 million premature deaths worldwide per year. So, it poses the greatest environmental risk to human health. A strong and rapidly expanding body of evidence links ambient air pollution to respiratory and cardiovascular conditions that eventually may also affect cognition in the elderly. Among various ambient air pollutants, particulate matter (PM) has been implicated as a chronic source of neuroinflammation and reactive oxygen species that produce neuropathology resulting in neurodevelopmental disorders and neurodegenerative disease. The current review will briefly discuss the clinical features and underlying mechanism of PM induced cognitive dysfunction, more specifically, dementia.

Where is the cleanest air quality in Sejong?

Your cart is empty

Connect With IQAir

Sign up for our newsletter

chat button icon
Chat or Call 866-488-1918
We're Online