Air quality in Koh Samui today
The air in Koh Samui (Thailand) now and over the next 48 hours: the US AQI and the European AQI, fine particles (PM2.5, PM10), ozone and nitrogen dioxide, compared with the WHO 2021 guidelines, with what it means for outdoor sport, children, older people and open windows.
These numbers are more than 7 hours old, so they are hidden. Open the live map for the current air. Open the air map centred on Koh Samui
AQI right now
Good. Main pollutant: Ozone (O₃) (all pollutants within the WHO guidelines).
What to do today
- Outdoor sport Go ahead: running, cycling and play outside carry no air-quality risk.
- Children, older people, asthma No restrictions.
- Windows Open them and air the rooms.
AQI in Koh Samui hour by hour, next 48 hours
- Good
- Moderate
- Unhealthy for sensitive groups
- Unhealthy
- Very unhealthy
- Hazardous
Cleanest hour in the next 24 h: Sun 08:00 (AQI 33). Worst hour: Sun 17:00 (AQI 39).
US AQI per hour, local time. Bars coloured by category.
Compared with the WHO 2021 guidelines
| Pollutant | Next 24 h | WHO guideline | Ratio |
|---|---|---|---|
| PM2.5 | 1.3 µg/m³ | 15 µg/m³ | within |
| PM10 | 1.6 µg/m³ | 45 µg/m³ | within |
| Nitrogen dioxide (NO₂) | 0.6 µg/m³ | 25 µg/m³ | within |
| Ozone (O₃) | 85 µg/m³ | 100 µg/m³ | within |
PM2.5, PM10 and NO₂: 24-hour mean of the forecast against the 24-hour guideline; ozone: highest 8-hour mean against the 8-hour guideline.
Forecast for Sun 04:00 local time · updated 2026-10-24 21:41 UTC
Air quality map around Koh Samui
Live PM2.5 field (NOAA GEFS-Aerosols): a different model, so it can disagree with the numbers above by a few units.
More about Koh Samui
Bad air alert for Koh Samui
Air quality alerts are part of LayEarth Pro: one push the evening before the forecast US AQI in your city goes above your level, so you can move a run, a school trip or an open window in time. 7-day free trial, then 9 USD a month.
Questions
- What is the AQI in Koh Samui right now?
- US AQI 38 (Good), European AQI 25; PM2.5 1.2 µg/m³ (Sun 04:00).
- Is it safe to exercise outdoors in Koh Samui today?
- Go ahead: running, cycling and play outside carry no air-quality risk.
- What is the main pollutant in Koh Samui?
- Ozone (O₃) (all pollutants within the WHO guidelines).
- Where do the numbers come from?
- The CAMS global air-quality forecast of the Copernicus Atmosphere Monitoring Service, read through Open-Meteo: a model on a ~40 km grid, not a monitoring station. Where a nearby monitor disagrees, the monitor is right.
Nearby cities
How it is computed
Hourly CAMS forecast (Copernicus) for the coordinates of Koh Samui via Open-Meteo; US AQI per the US EPA breakpoints, European AQI per the EEA bands, WHO 2021 air-quality guidelines. The page is rebuilt every 3 hours. Live map.