Is the air in Seoul safe today?

No. Right now the US AQI in Seoul is 158, which counts as unhealthy. Everyone should cut back on outdoor exercise. Sensitive groups should stay indoors.

When is the best time to be outside in Seoul?

Sat 13:00–16:00. That is the cleanest stretch in the next 24 hours, with the US AQI averaging about 99. The worst hour is around Sat 02:00, at 158.

What is the main pollutant in Seoul?

Fine particles (PM2.5). It drives the index right now, at 65 µg/m³. Tiny particles from combustion, fires and dust that reach deep into the lungs. The main driver of AQI worldwide.

How does Seoul's air compare with the WHO guideline?

2.7 times the guideline. Over the next 24 hours PM2.5 averages about 41 µg/m³, against the World Health Organization's 24-hour guideline of 15 µg/m³. NO2 and SO2 are also forecast above their guideline levels.

How many cigarettes is a day of Seoul's air?

About 1.9 cigarettes. Over the next 24 hours PM2.5 averages about 41 µg/m³. By Berkeley Earth's rule of thumb, 22 µg/m³ breathed for a day is roughly one cigarette.

Will air quality in Seoul improve this week?

Sunday looks cleanest. Its AQI peaks at 102, against 169 on Saturday, the worst day in the forecast.

Seoul air quality

South Korea · Live AQI and hourly forecast for the next 5 days · valid Sat 02:00 local time

158

Unhealthy

US AQI, mostly PM_2.5

Model estimate. Nearby measurements are shown separately.

Everyone should cut back on outdoor exercise. Sensitive groups should stay indoors.

Next 24 hours: 93–158US AQI, highest around Sat 02:00
Best time outside: Sat 13:00–16:00US AQI about 99
PM_2.5 vs WHO guideline: 2.7×41 µg/m³ over 24 h, guideline 15
Cigarette equivalent: ≈ 1.9 a dayBerkeley Earth rule of thumb

Loading the live globe…

The live globe, centred on Seoul. Switch pollutants, drag through the next 5 days or press play. Full map →

Pollutants in Seoul right now

Pollutant	Now	Level	Next 24 h vs WHO
Fine particles PM_2.5	65 µg/m³	Unhealthy	2.7×
Coarse particles PM₁₀	69 µg/m³	Moderate	1.0×
Nitrogen dioxide NO₂	61 µg/m³	Good	2.3×
Ozone O₃	0.0 µg/m³	Good	0.0×
Sulphur dioxide SO₂	68 µg/m³	Good	1.0×
Carbon monoxide CO	1,225 µg/m³	Good	0.2×
Aerosol optical depth	0.30	Whole atmosphere · dimensionless
Desert dust	1 µg/m³	Modelled surface dust
UV index	0	Low

“Next 24 h vs WHO” compares the forecast with the World Health Organization’s 2021 guideline levels: 24-hour means of 15 µg/m³ for PM_2.5, 45 for PM₁₀, 25 for NO₂, 40 for SO₂ and 4 mg/m³ for CO, and 100 µg/m³ over 8 hours for ozone. Above 1× is above the guideline. Levels follow the US AQI, which is far less strict than the WHO, so air rated Good can still be above a guideline.

Next 48 hours

Hourly US AQI. Highest 158 around Sat 02:00, lowest 32 around Sun 12:00.

50100150

Good 0–50Moderate 51–100Sensitive 101–150Unhealthy 151–200Very unhealthy 201–300Hazardous 301+

5-day air quality forecast for Seoul

Daily range of the hourly US AQI, from lowest to highest, on a scale of 0 to 200.

Day	US AQI	At worst	Worst hour	PM_2.5 avg	UV max
Sat 14 Nov	98–169	Unhealthy	0:00	44	1 Low
Sun 15 Nov	32–102	Sensitive	0:00	19	3 Moderate
Mon 16 Nov	28–106	Sensitive	1:00	14	1 Low
Tue 17 Nov	37–115	Sensitive	18:00	20	2 Low

Common questions about the air in Seoul

Is the air in Seoul safe today?
No. Right now the US AQI in Seoul is 158, which counts as unhealthy. Everyone should cut back on outdoor exercise. Sensitive groups should stay indoors.
When is the best time to be outside in Seoul?
Sat 13:00–16:00. That is the cleanest stretch in the next 24 hours, with the US AQI averaging about 99. The worst hour is around Sat 02:00, at 158.
What is the main pollutant in Seoul?
Fine particles (PM_2.5). It drives the index right now, at 65 µg/m³. Tiny particles from combustion, fires and dust that reach deep into the lungs. The main driver of AQI worldwide.
How does Seoul's air compare with the WHO guideline?
2.7 times the guideline. Over the next 24 hours PM_2.5 averages about 41 µg/m³, against the World Health Organization's 24-hour guideline of 15 µg/m³. NO₂ and SO₂ are also forecast above their guideline levels.
How many cigarettes is a day of Seoul's air?
About 1.9 cigarettes. Over the next 24 hours PM_2.5 averages about 41 µg/m³. By Berkeley Earth's rule of thumb, 22 µg/m³ breathed for a day is roughly one cigarette.
Will air quality in Seoul improve this week?
Sunday looks cleanest. Its AQI peaks at 102, against 169 on Saturday, the worst day in the forecast.

Measured near Seoul

Station and measurements	Distance	US AQI	Level
중구 OpenAQ, reference monitor PM_2.5: 41 µg/m³ · Sat 02:00 NO₂: 72 µg/m³ · Sat 02:00 O₃: 28 µg/m³ · Sat 02:00 SO₂: 7.3 µg/m³ · Sat 02:00 CO: 664 µg/m³ · Sat 02:00	0.3 km	115	Sensitive
종로 OpenAQ, reference monitor PM_2.5: 32 µg/m³ · Sat 02:00 O₃: 7.3 µg/m³ · Sat 02:00 SO₂: 8.1 µg/m³ · Sat 02:00 CO: 744 µg/m³ · Sat 02:00	1.7 km	94	Moderate
청계천로 OpenAQ, reference monitor PM_2.5: 32 µg/m³ · Sat 02:00 PM₁₀: 52 µg/m³ · Sat 02:00 NO₂: 78 µg/m³ · Sat 02:00 O₃: 7.6 µg/m³ · Sat 02:00 SO₂: 6.6 µg/m³ · Sat 02:00 CO: 721 µg/m³ · Sat 02:00	1.8 km	94	Moderate

Air quality near Seoul

US AQI right now. Cleanest nearby: Busan (126); worst: Beijing (283). The tick on each bar is Seoul, at 158.

Busan 325 km SE 126 Sensitive
Osaka 829 km E 143 Sensitive
Shanghai 866 km SW 152 Unhealthy
Beijing 952 km W 283 Very unhealthy
Tokyo 1,149 km E 153 Unhealthy
Wuhan 1,399 km SW 168 Unhealthy

All 162 cities →

About this forecast

Forecast from CAMS global via Open-Meteo: the Copernicus Atmosphere Monitoring Service (CAMS) model at about 40 km resolution (about 10 km inside Europe). Global runs update every 12 hours and European runs every 24 hours. Models smooth out street-level peaks, so busy roads and industrial sites can be worse than shown. Nearby station measurements are independent observations, not adjustments to the forecast. The point forecast uses Open-Meteo’s CAMS products, including a separate carbon monoxide product; it can differ from the globe’s global grid. The AQI rates each hour on the US EPA scale, the same way the map colors it; official daily figures average over 24 hours (8 for ozone), so they can read lower after a short peak. Readings for 37.57°N, 126.98°E, valid 2026-11-13 17:00 UTC.