Worst air pollution Ansan, today and tomorrow

Today (16 July): Air quality in Ansan is fair. PM2.5 and PM1 are fair; AQI, NO2, and O3 are medium; PM10, SO2, CO, and HCHO are good. Pollution peaks around 9:00 PM (NO2: 50.4/100).
Tomorrow (17 July 2026): Air quality in Ansan is very poor. AQI worsens to very poor; NO2 increases to poor; O3 increases to very poor; SO2 increases to medium; PM1 decreases to medium; all other pollutants stay as today. Pollution peaks around 4:00 PM (O3: 81.8/100). Airmine updates local air quality forecasts four times daily.

For long term forecasts and maps, see the Airmine app

Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team

Use our Strava plugin to check your own exposure.

Ansan's air quality reflects the flat Gyeonggi-do western Seoul metropolitan Siheung coastal industrial corridor, with vehicle traffic on surrounding expressways and the semiconductor, chemical, and manufacturing complex generating elevated industrial PM2.5. Yellow Sea breezes provide coastal ventilation, while seasonal Chinese dust transport elevates PM10 and the extraordinary manufacturing density makes Ansan South Korea's most distinctively multi-national industrial park-defined metropolitan environment throughout most of the year.

Today - 16 July | Pollution peaks at 21:00

AQI:

Medium

50.4/100

PM2.5 (fine particles):

Fair

25.0/100

PM10 (coarse particles):

Good

12.9/100

NO2 (nitrogen dioxide):

Medium

50.4/100

O3 (ozone):

Medium

49.9/100

SO2 (sulfur dioxide):

Good

19.6/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

5.2/100

PM1 (ultrafine particles):

Fair

23.3/100

Levels show the poorest local air quality during the day

Tomorrow - 17 July | Pollution peaks at 16:00

AQI:

Very poor

81.8/100

PM2.5 (fine particles):

Fair

34.8/100

PM10 (coarse particles):

Good

10.8/100

NO2 (nitrogen dioxide):

Poor

63.4/100

O3 (ozone):

Very poor

81.8/100

SO2 (sulfur dioxide):

Medium

40.6/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

16.5/100

PM1 (ultrafine particles):

Medium

40.3/100

Frequently Asked Questions

Is air quality bad in Ansan right now?

On 16 July 2026, overall air quality in Ansan is fair. PM2.5 is the main pollutant at 25.0/100. Pollution peaks around 9:00 PM (NO2: 50.4/100).

Will air quality be worse tomorrow in Ansan?

On 17 July 2026, air quality conditions in Ansan will be worse than today, with AQI forecast at very poor at 81.8/100. Pollution peaks around 4:00 PM (O3: 81.8/100).

When is air pollution at its worst in Ansan?

Ansan usually sees its poorest air quality when traffic emissions, heavy industrial and chemical processing, along with light manufacturing coincide with periods when windblown dust events occur. Strong seasonal winds can lift dust from the surrounding dry terrain and push particulate levels sharply higher. Sea breezes typically keep conditions in check, except during still weather.

Are air quality levels in Ansan based on measurements or forecasts?

It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.

Check air quality in other popular cities:

Data provided by Airmine — Last update: 16 July 2026 at 10:33 CEST (Data is updated four times daily.)

This forecast is produced independently using Airmine's own atmospheric data and models.

Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.

For long term forecasts and maps, see the Airmine app