Fine particles
10.1µg/m³Fair · 1 hourCAMS model • Open-Meteo
Chiang MaiAir quality, PM2.5 and PM10
Check PM2.5 and PM10 particle levels alongside ozone, nitrogen dioxide and other gases. Compare the latest available concentrations with recent days and explore changes in air pollution through the available historical records.
Chiang Mai - latest available concentrations (November 11, 2026, 09:00 local time): PM2.5: 10.1 µg/m³, PM10: 10.3 µg/m³, O₃: 40 µg/m³, NO₂: 15.7 µg/m³, SO₂: 6.1 µg/m³, CO: 746 µg/m³. These are hourly CAMS model values for a point representing the city.
Air quality questions →
1 weather warning in effect for Thailand
Chiang Mai · Air pollutant concentrations
Data time: November 11, 2026 · 09:00 · local timeParticulate matter
10.3µg/m³Good · 1 hourOzone
40µg/m³Good · 1 hourNitrogen dioxide
15.7µg/m³Fair · 1 hourSulphur dioxide
6.1µg/m³Good · 1 hourCarbon monoxide
746µg/m³PM2.5 vs PM10 - what is the difference? → · Models and monitoring stations →
DAILY DATA · Chiang Mai
Chiang Mai - air pollution over recent days (2026-08-31 - 2026-11-10)
Concentrations of all available pollutants for this city.
PM2.5Lowest 6.68 2026-11-10Highest 17.29 2026-11-062026-08-31 - 2026-11-10
PM10Lowest 6.78 2026-11-10Highest 18.25 2026-09-042026-08-31 - 2026-11-10
O₃Lowest 38.38 2026-09-01Highest 73.17 2026-11-062026-08-31 - 2026-11-10
NO₂Lowest 12.42 2026-09-07Highest 27.42 2026-11-042026-08-31 - 2026-11-10
SO₂Lowest 3.09 2026-09-07Highest 7.95 2026-11-072026-08-31 - 2026-11-10
COLowest 606.21 2026-11-10Highest 1,832.88 2026-09-042026-08-31 - 2026-11-10
Scroll the chart or table sideways to see the full period.
| Pollutant | 2026-11-10 | 2026-11-09 | 2026-11-08 | 2026-11-07 | 2026-11-06 | 2026-11-05 | 2026-11-04 | 2026-09-07 | 2026-09-06 | 2026-09-05 | 2026-09-04 | 2026-09-03 | 2026-09-02 | 2026-09-01 | 2026-08-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 | 6.68 | 9.64 | 8.84 | 9.54 | 17.29 | 11.06 | 12.1 | 7.16 | 14.93 | 12.13 | 14.43 | 12.79 | 15.5 | 15.63 | 11.62 |
| PM10 | 6.78 | 10.12 | 9.06 | 9.57 | 17.33 | 11.1 | 12.13 | 7.5 | 17.18 | 13.72 | 18.25 | 14.18 | 17.6 | 17.14 | 13.04 |
| O₃ | 60.08 | 57.79 | 56.79 | 71.08 | 73.17 | 72.33 | 66.29 | 43.79 | 46.04 | 40.79 | 45.08 | 43.38 | 38.54 | 38.38 | 38.71 |
| NO₂ | 14.98 | 17.58 | 15.33 | 15.78 | 23.08 | 23.34 | 27.42 | 12.42 | 15.93 | 18.65 | 16.91 | 20.58 | 18.83 | 22.91 | 19.32 |
| SO₂ | 5.01 | 5.83 | 6.4 | 7.95 | 7.57 | 6.08 | 7.58 | 3.09 | 3.83 | 4.82 | 4.46 | 5.82 | 6.33 | 7.52 | 5.21 |
| CO | 606.21 | 788.58 | 1,109.42 | 1,036.42 | 1,215.29 | 1,156.04 | 1,588.17 | 837.96 | 1,032.13 | 1,818.42 | 1,832.88 | 1,378.13 | 1,251.88 | 1,410.33 | 1,091.29 |
A dot on the chart and a dash in the table indicate missing data. The latest day may be incomplete.
AIR QUALITY ARCHIVE · Chiang Mai
Chiang Mai - air pollution history (2015-10 - 2020-05)
Compare monthly particle and gas concentrations in the available archive.
PM10Lowest 21.6 2018-09Highest 118 2016-042015-10 - 2020-05
NO₂ (ppm)Lowest 0.00642 2019-07Highest 0.0463 2018-072015-10 - 2020-05
SO₂ (ppm)Lowest 0.001 2015-10Highest 0.0023 2016-042015-10 - 2020-05
CO (ppm)Lowest 0.463 2019-07Highest 1.46 2016-042015-10 - 2020-05
Scroll the chart or table sideways to see the full period.
| Pollutant | 2020-05 | 2020-04 | 2020-03 | 2020-02 | 2020-01 | 2019-12 | 2019-11 | 2019-10 | 2019-09 | 2019-08 | 2019-07 | 2019-06 | 2019-05 | 2019-04 | 2019-03 | 2019-02 | 2019-01 | 2018-12 | 2018-11 | 2018-10 | 2018-09 | 2018-08 | 2018-07 | 2018-06 | 2018-05 | 2018-04 | 2018-03 | 2018-02 | 2018-01 | 2017-12 | 2017-11 | 2017-10 | 2017-09 | 2017-08 | 2017-07 | 2017-06 | 2017-05 | 2017-04 | 2017-03 | 2017-02 | 2017-01 | 2016-12 | 2016-11 | 2016-10 | 2016-09 | 2016-08 | 2016-07 | 2016-06 | 2016-05 | 2016-04 | 2016-03 | 2016-02 | 2016-01 | 2015-12 | 2015-11 | 2015-10 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM10 µg/m³ | 30.1 | 79.8 | 109 | 88 | 69.4 | 59 | 47.2 | 37.3 | 34.2 | 28.6 | 30.4 | 26.7 | 49.8 | 82.6 | 103 | 59.6 | 35.7 | 29.4 | 29.7 | 23.5 | 21.6 | 30.9 | 36.2 | 38.3 | 33.2 | 61.4 | 85.6 | 64 | 39.9 | 41.5 | 39.1 | 38.3 | 36.7 | 40.2 | 36 | 35.3 | 47 | 67.1 | 69.2 | 58.9 | 36.3 | 38.9 | 32.4 | 28.5 | 27.9 | 29.7 | 28.1 | 24.5 | 49.5 | 118 | 107 | 82.2 | 57.8 | 46.6 | 35.3 | 48.3 |
| NO₂ (ppm) | — | — | 0.0218 | 0.0261 | 0.0253 | 0.0212 | 0.0158 | 0.0107 | 0.00923 | 0.00903 | 0.00642 | 0.0077 | 0.014 | 0.0209 | 0.0263 | 0.0254 | 0.0189 | 0.0162 | 0.0154 | 0.0112 | 0.0111 | 0.0265 | 0.0463 | 0.0112 | 0.0124 | 0.0152 | 0.0266 | 0.0224 | 0.0153 | 0.0174 | 0.0137 | 0.011 | 0.0106 | 0.0101 | 0.0103 | 0.0104 | 0.0131 | 0.0168 | 0.0195 | 0.0383 | 0.0135 | 0.0162 | 0.0167 | 0.0124 | 0.0128 | 0.013 | 0.0114 | 0.011 | 0.0189 | 0.0308 | 0.0307 | 0.0283 | 0.0245 | 0.0214 | 0.0171 | 0.018 |
| SO₂ (ppm) | 0.00117 | 0.00177 | 0.0017 | 0.00141 | 0.00106 | 0.001 | 0.001 | 0.001 | 0.001 | 0.00219 | 0.00126 | 0.001 | 0.00106 | 0.00167 | 0.00187 | 0.0015 | 0.00119 | 0.00177 | 0.0018 | 0.001 | 0.001 | 0.00103 | 0.001 | 0.001 | 0.001 | 0.0013 | 0.00171 | 0.00136 | 0.00103 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.00107 | 0.00131 | 0.00111 | 0.001 | 0.001 | 0.00103 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.0011 | 0.0023 | 0.00145 | 0.00104 | 0.001 | 0.001 | 0.001 | 0.001 |
| CO (ppm) | 0.548 | 0.884 | 1.14 | 0.961 | 0.888 | 0.827 | 0.84 | 1.15 | 0.616 | 0.541 | 0.463 | 0.498 | 0.638 | 1.08 | 1.22 | 0.935 | 0.861 | 0.94 | 0.84 | 0.761 | 0.644 | 0.684 | 0.694 | 0.597 | 0.624 | 0.84 | 1.02 | 0.992 | 0.904 | 0.86 | 0.849 | 0.672 | 0.571 | 0.543 | 0.611 | 0.692 | 0.647 | 0.891 | 0.985 | 1.14 | 1.13 | 0.941 | 0.937 | 0.889 | 0.99 | 0.843 | 0.863 | 0.931 | 0.892 | 1.46 | 1.29 | 1.45 | 1.11 | 1.01 | 0.889 | 1.09 |
A dot on the chart and a dash in the table indicate missing data. Historical values do not describe today’s air quality.
Historical data by station 1
AIR QUALITY ARCHIVE · Si Phum, Mueang
Si Phum, Mueang
Station code: Si Phum, Mueang
Monthly monitoring station data.
PM10Lowest 21.6 2018-09Highest 118 2016-042015-10 - 2020-05
NO₂ (ppm)Lowest 0.00642 2019-07Highest 0.0463 2018-072015-10 - 2020-05
SO₂ (ppm)Lowest 0.001 2015-10Highest 0.0023 2016-042015-10 - 2020-05
CO (ppm)Lowest 0.463 2019-07Highest 1.46 2016-042015-10 - 2020-05
Scroll the chart or table sideways to see the full period.
| Pollutant | 2020-05 | 2020-04 | 2020-03 | 2020-02 | 2020-01 | 2019-12 | 2019-11 | 2019-10 | 2019-09 | 2019-08 | 2019-07 | 2019-06 | 2019-05 | 2019-04 | 2019-03 | 2019-02 | 2019-01 | 2018-12 | 2018-11 | 2018-10 | 2018-09 | 2018-08 | 2018-07 | 2018-06 | 2018-05 | 2018-04 | 2018-03 | 2018-02 | 2018-01 | 2017-12 | 2017-11 | 2017-10 | 2017-09 | 2017-08 | 2017-07 | 2017-06 | 2017-05 | 2017-04 | 2017-03 | 2017-02 | 2017-01 | 2016-12 | 2016-11 | 2016-10 | 2016-09 | 2016-08 | 2016-07 | 2016-06 | 2016-05 | 2016-04 | 2016-03 | 2016-02 | 2016-01 | 2015-12 | 2015-11 | 2015-10 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM10 µg/m³ | 30.1 | 79.8 | 109 | 88 | 69.4 | 59 | 47.2 | 37.3 | 34.2 | 28.6 | 30.4 | 26.7 | 49.8 | 82.6 | 103 | 59.6 | 35.7 | 29.4 | 29.7 | 23.5 | 21.6 | 30.9 | 36.2 | 38.3 | 33.2 | 61.4 | 85.6 | 64 | 39.9 | 41.5 | 39.1 | 38.3 | 36.7 | 40.2 | 36 | 35.3 | 47 | 67.1 | 69.2 | 58.9 | 36.3 | 38.9 | 32.4 | 28.5 | 27.9 | 29.7 | 28.1 | 24.5 | 49.5 | 118 | 107 | 82.2 | 57.8 | 46.6 | 35.3 | 48.3 |
| NO₂ (ppm) | — | — | 0.0218 | 0.0261 | 0.0253 | 0.0212 | 0.0158 | 0.0107 | 0.00923 | 0.00903 | 0.00642 | 0.0077 | 0.014 | 0.0209 | 0.0263 | 0.0254 | 0.0189 | 0.0162 | 0.0154 | 0.0112 | 0.0111 | 0.0265 | 0.0463 | 0.0112 | 0.0124 | 0.0152 | 0.0266 | 0.0224 | 0.0153 | 0.0174 | 0.0137 | 0.011 | 0.0106 | 0.0101 | 0.0103 | 0.0104 | 0.0131 | 0.0168 | 0.0195 | 0.0383 | 0.0135 | 0.0162 | 0.0167 | 0.0124 | 0.0128 | 0.013 | 0.0114 | 0.011 | 0.0189 | 0.0308 | 0.0307 | 0.0283 | 0.0245 | 0.0214 | 0.0171 | 0.018 |
| SO₂ (ppm) | 0.00117 | 0.00177 | 0.0017 | 0.00141 | 0.00106 | 0.001 | 0.001 | 0.001 | 0.001 | 0.00219 | 0.00126 | 0.001 | 0.00106 | 0.00167 | 0.00187 | 0.0015 | 0.00119 | 0.00177 | 0.0018 | 0.001 | 0.001 | 0.00103 | 0.001 | 0.001 | 0.001 | 0.0013 | 0.00171 | 0.00136 | 0.00103 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.00107 | 0.00131 | 0.00111 | 0.001 | 0.001 | 0.00103 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.0011 | 0.0023 | 0.00145 | 0.00104 | 0.001 | 0.001 | 0.001 | 0.001 |
| CO (ppm) | 0.548 | 0.884 | 1.14 | 0.961 | 0.888 | 0.827 | 0.84 | 1.15 | 0.616 | 0.541 | 0.463 | 0.498 | 0.638 | 1.08 | 1.22 | 0.935 | 0.861 | 0.94 | 0.84 | 0.761 | 0.644 | 0.684 | 0.694 | 0.597 | 0.624 | 0.84 | 1.02 | 0.992 | 0.904 | 0.86 | 0.849 | 0.672 | 0.571 | 0.543 | 0.611 | 0.692 | 0.647 | 0.891 | 0.985 | 1.14 | 1.13 | 0.941 | 0.937 | 0.889 | 0.99 | 0.843 | 0.863 | 0.931 | 0.892 | 1.46 | 1.29 | 1.45 | 1.11 | 1.01 | 0.889 | 1.09 |
A dot on the chart and a dash in the table indicate missing data. Historical values do not describe today’s air quality.
How should I interpret the data and averaging period? →
OpenAQ ↗Thailand
Environment and quality of life ratings · Chiang Mai
Archived ratings of the local environment: green spaces, cleanliness, noise and water quality. Opinion indicators are separate from pollutant concentration measurements.
| Indicator | Chiang Mai | laoPDR | Cambodia | Vietnam | Myanmar | Malaysia |
|---|---|---|---|---|---|---|
| Green and Parks in the City | 43% | 37% | 36% | 42% | 33% | 54% |
| particulate matter PM2.5 (µg/m³) | 25 | — | — | — | — | — |
| Pleasure of spending time in the city | 32% | 38% | 32% | 30% | 24% | 48% |
| particulate matter PM10 (µg/m³) | 46 | — | — | — | — | — |
| Air Pollution | 81% | 72% | 68% | 78% | 83% | 53% |
| Garbage Disposal | 51% | 20% | 25% | 24% | 12% | 47% |
| Availability and quality of drinking water | 55% | 51% | 48% | 43% | 34% | 56% |
| Cleanliness and tidiness | 49% | 32% | 25% | 29% | 18% | 47% |
| Noise and Light pollution | 55% | 55% | 59% | 65% | 52% | 49% |
| Water Pollution | 60% | 73% | 73% | 73% | 74% | 62% |
Air quality in nearby cities
All cities →Thailand↗
Lampang
PM2.55.8
PM106.1
µg/m³
PM2.5 · FairNO₂ 3.2O₃ 58
November 11, 202609:00
Thailand↗
Phitsanulok
PM2.57
PM108.1
µg/m³
PM2.5 · FairNO₂ 6.5O₃ 80
November 11, 202609:00
Thailand↗
Udon Thani
PM2.58.7
PM109.6
µg/m³
PM2.5 · FairNO₂ 2.2O₃ 76
November 11, 202609:00
Thailand↗
Khon Kaen
PM2.511.2
PM1012
µg/m³
PM2.5 · FairNO₂ 4.9O₃ 78
November 11, 202609:00
Thailand↗
Nakhon Ratchasima
PM2.510.4
PM1011.3
µg/m³
PM2.5 · FairNO₂ 3.3O₃ 82
November 11, 202609:00
Thailand↗
Khlong Luang District
PM2.57.2
PM107.5
µg/m³
PM2.5 · FairNO₂ 6.9O₃ 82
November 11, 202609:00
Thailand↗
Rangsit
PM2.57.2
PM107.5
µg/m³
PM2.5 · FairNO₂ 6.9O₃ 82
November 11, 202609:00
Thailand↗
Nakhon Pathom
PM2.58.1
PM108.3
µg/m³
PM2.5 · FairNO₂ 10O₃ 77
November 11, 202609:00
Thailand · air quality in other cities
WEATHER & SURROUNDINGS
Thailand · weather forecast
Daily maximum and minimum temperatures. Forecast point: 15.87, 100.9925. Forecast for a country reference point; conditions in the city may differ.
Scroll the forecast to see the following days.
Thailand · November 9, 2026: minimum temperature 25.3°C, maximum 31.3°C. Wind: 24 km/h. Humidity: 72%.
Full forecast: temperature, rainfall, wind and humidity
| Date | Day °C | Min °C | Max °C | Night °C | Rain mm | Wind m/s | Humidity % | Clouds % |
|---|---|---|---|---|---|---|---|---|
| 2026-11-09 | 28.5 | 25.3 | 31.3 | 26.1 | 0.5 | 6.7 | 72 | 11 |
| 2026-11-10 | 26.1 | 23.3 | 28.9 | 23.3 | 0.2 | 7 | 67 | 19 |
| 2026-11-11 | 27 | 22.3 | 28.3 | 24.1 | 0.1 | 3.2 | 63 | 92 |
| 2026-11-12 | 27 | 20.6 | 27.3 | 22.4 | 0.3 | 2.8 | 65 | 97 |
| 2026-11-13 | 29.1 | 21.5 | 29.1 | 23.3 | 0.2 | 2.1 | 63 | 19 |
| 2026-11-14 | 30.5 | 21.9 | 30.5 | 24.3 | 0.6 | 2.3 | 62 | 31 |
| 2026-11-15 | 31.1 | 22.6 | 31.1 | 25.2 | 0.3 | 1.8 | 62 | 99 |
| 2026-11-16 | 29.8 | 23 | 29.8 | 24.3 | 14.2 | 1.8 | 71 | 72 |
| 2026-11-17 | 28.3 | 23.5 | 28.9 | 24.8 | 15.2 | 1 | 78 | 94 |
| 2026-11-18 | 29.1 | 23.4 | 29.1 | 24.8 | 17.9 | 1.5 | 73 | 73 |
| 2026-11-19 | 30.4 | 23.3 | 30.4 | 24.7 | 0.2 | 4.2 | 66 | 36 |
| 2026-11-20 | 30.1 | 22.9 | 30.1 | 24.3 | 14.2 | 2.5 | 66 | 43 |
| 2026-11-21 | 28.9 | 21.9 | 28.9 | 23 | 9.1 | 2.8 | 63 | 3 |
| 2026-11-22 | 30 | 21.2 | 30 | 24.1 | 10.2 | 2.1 | 61 | 25 |
| 2026-11-23 | 30.8 | 22.2 | 31.1 | 24.4 | — | 1.7 | 62 | 66 |
| 2026-11-24 | 31 | 22.6 | 31.4 | 25 | — | 2.2 | 58 | 41 |
| 2026-11-25 | 30.5 | 23 | 30.6 | 25.2 | — | 2.1 | 59 | 78 |
UV index by day · Thailand
Data for a country reference point. Local conditions may differ.
SPF 30-50, hat and sunglasses are a must. Better to stay in the shade 11:00-15:00.
0-2 low3-5 moderate6-7 high8-10 very high11+ extreme
Scroll the forecast to see the following days.
Thailand · November 10, 2026: UV index: 7 .
| Indicator | 2026-11-10 | 2026-11-11 | 2026-11-12 | 2026-11-13 | 2026-11-14 | 2026-11-15 | 2026-11-16 | 2026-11-17 | 2026-11-18 | 2026-11-19 | 2026-11-20 | 2026-11-21 | 2026-11-22 | 2026-11-23 | 2026-11-24 | 2026-11-25 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index | 7 | 6 | 6.3 | 7 | 7 | 6.9 | 7 | 4.6 | 6.6 | 6.7 | 6.8 | 6.8 | 6.8 | 6.7 | 6.7 | — |
AIR QUALITY QUESTIONS
Chiang Mai · air pollution - questions and answers
What do the latest air quality data show for Chiang Mai?
Chiang Mai - latest available concentrations (November 11, 2026, 09:00 local time): PM2.5: 10.1 µg/m³, PM10: 10.3 µg/m³, O₃: 40 µg/m³, NO₂: 15.7 µg/m³, SO₂: 6.1 µg/m³, CO: 746 µg/m³. These are hourly CAMS model values for a point representing the city.
When was PM2.5 highest in Chiang Mai over the past week?
The highest available daily mean PM2.5 was 17.3 µg/m³ (November 6, 2026). This comparison covers 7 days with data in the seven days before November 11, 2026. The day of the latest reading is excluded because it may be incomplete.
What period does the pollution history for Chiang Mai cover?
Available monthly means cover 2015-10 - 2020-05. The tables include PM10, NO₂ (ppm), SO₂ (ppm), CO (ppm). Missing values are marked with a dash, not treated as zero. Monthly archives and current model data may come from different sources.
Is the PM2.5 concentration for Chiang Mai an AQI score?
No. PM2.5 and PM10 are concentrations in µg/m³. AQI is a separate index calculated using a defined scale. When comparing air quality, also check other pollutants, the date and the averaging period.
What UV index does the available forecast show for Chiang Mai?
For November 10, 2026, the forecast UV index is 7. The UV section also shows the following available days. The forecast is for a country reference point (Thailand), not the city itself.
What wind speed is forecast for Chiang Mai?
For November 9, 2026, forecast wind speed is 24 km/h. The weather table includes wind, temperature and other available parameters for subsequent days. These data describe a country reference point (Thailand); local wind may differ.
PM2.5 · PM10 · NO₂ · O₃
Understanding air quality and pollution data
What do PM2.5 and PM10 mean?
PM2.5 and PM10 are fractions of airborne particulate matter. PM2.5 covers fine particles up to 2.5 micrometres in diameter, while PM10 covers particles up to 10 micrometres. Concentrations in µg/m³ tell you how many micrograms of particles are present in a cubic metre of air. Compare values over the same time period.
Where does the air pollution data come from?
The latest concentrations come from the CAMS atmospheric model via Open-Meteo for each city’s coordinates. Values describe a model area, so conditions on individual streets may differ. Historical monitoring station data is shown separately where available.
How does PM2.5 concentration differ from AQI?
PM2.5 is the concentration of one particle fraction, expressed in µg/m³. AQI is an index calculated using a particular scale and thresholds. The pollutant cards show concentrations. Our city ranking compares PM2.5; PM10, ozone, nitrogen dioxide and other available gases add to the picture of air quality.
Which dates do the values and charts cover?
Each current value has a data date and time. Current concentration cards show the latest available hour, daily charts summarise individual days, and monthly records let you compare longer periods. These values represent different time intervals.
How can I check pollution in my city?
Search for your city and open its air quality page. Start with PM2.5 and PM10, then check the other available pollutants and the data timestamp. Charts and tables help you compare concentrations over time. Weather and historical climate information complement the pollution data.