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Chiang Mai air quality

Thailand · Live AQI and hourly forecast for the next 5 days · updated Sun 07:00 local time

59

Moderate

US AQI, mostly PM2.5

Acceptable. Unusually sensitive people should ease off long, intense outdoor effort.

Next 24 hours
37–62US AQI, highest around Sun 10:00
Best time outside
Mon 04:00–7:00US AQI about 41
PM2.5 vs WHO guideline
0.4×6.0 µg/m³ over 24 h, guideline 15
Cigarette equivalent
≈ 0.3 a dayBerkeley Earth rule of thumb
European AQI
Moderatelevel 3 of 6

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

Pollutants in Chiang Mai right now

PollutantNowNext 24 h vs WHOUS AQI band
Fine particles (PM2.5) 21 µg/m³ 0.4× Moderate
Coarse particles (PM10) 21 µg/m³ 0.1× Good
Nitrogen dioxide (NO2) 32 µg/m³ 0.4× Good
Ozone (O3) 16 µg/m³ 0.8× Good
Sulphur dioxide (SO2) 9.2 µg/m³ 0.2× Good
Carbon monoxide (CO) 1,048 µg/m³ 0.1× Good
Desert dust0 µg/m³
Smoke and haze (aerosol optical depth)0.18
UV index0.3

“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 PM2.5, 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.

Next 48 hours

Hourly US AQI. Highest 62 around Sun 10:00, lowest 22 around Tue 05:00.

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

5-day air quality forecast for Chiang Mai

Daily range of the hourly US AQI, from lowest to highest, on a scale of 0 to 150.

DayUS AQIAt worstWorst hourPM2.5 avgUV max
Sun 27 Sept 54–62 Moderate 10:00 11 8.8
Mon 28 Sept 25–55 Moderate 0:00 4.6 4.2
Tue 29 Sept 21–37 Good 17:00 5.1 4.1
Wed 30 Sept 28–68 Moderate 18:00 12 9.9
Thu 1 Oct 56–107 Sensitive 18:00 21 9.3

Common questions about the air in Chiang Mai

  1. Is the air in Chiang Mai safe today?

    For most people, yes. Right now the US AQI in Chiang Mai is 59, which counts as moderate. Acceptable. Unusually sensitive people should ease off long, intense outdoor effort.

  2. When is the best time to be outside in Chiang Mai?

    Mon 04:00–7:00. That is the cleanest stretch in the next 24 hours, with the US AQI averaging about 41. The worst hour is around Sun 10:00, at 62.

  3. What is the main pollutant in Chiang Mai?

    Fine particles (PM2.5). It drives the index right now, at 21 µg/m³. Tiny particles from combustion, fires and dust that reach deep into the lungs. The main driver of AQI worldwide.

  4. How does Chiang Mai's air compare with the WHO guideline?

    Within the guideline. Over the next 24 hours PM2.5 averages about 6.0 µg/m³, against the World Health Organization's 24-hour guideline of 15 µg/m³. The other pollutants stay within their guideline levels.

  5. How many cigarettes is a day of Chiang Mai's air?

    About 0.3 cigarettes. Over the next 24 hours PM2.5 averages about 6.0 µg/m³. By Berkeley Earth's rule of thumb, 22 µg/m³ breathed for a day is roughly one cigarette.

  6. Will air quality in Chiang Mai improve this week?

    Tuesday looks cleanest. Its AQI peaks at 37, against 107 on Thursday, the worst day in the forecast.

Measured near Chiang Mai

StationDistancePM2.5 µg/m³Measured
Unnamed sensor Sensor.Community, low-cost sensor 0.7 km 2.3 Sun 06:50

Air quality near Chiang Mai

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About this forecast

Forecast from CAMS global via Open-Meteo: the Copernicus Atmosphere Monitoring Service (CAMS) model at about 40 km resolution (10 km inside Europe), refreshed twice a day. Models smooth out street-level peaks, so busy roads and industrial sites can be worse than shown; ground stations, where there are any nearby, show what monitors actually measure. The US AQI follows the US EPA scale and the European AQI the EEA bands. Readings for 18.79°N, 98.99°E, updated 2026-09-27 00:00 UTC.