Fine particles
4.2µg/m³Good · 1 hourCAMS model • Open-Meteo
ChennaiAir 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.
Chennai - latest available concentrations (October 23, 2026, 06:30 local time): PM2.5: 4.2 µg/m³, PM10: 5.1 µg/m³, O₃: 63 µg/m³, NO₂: 5.3 µg/m³, SO₂: 3.8 µg/m³, CO: 266 µg/m³. These are hourly CAMS model values for a point representing the city.
Air quality questions →Chennai · Air pollutant concentrations
Data time: October 23, 2026 · 06:30 · local timeParticulate matter
5.1µg/m³Good · 1 hourOzone
63µg/m³Fair · 1 hourNitrogen dioxide
5.3µg/m³Good · 1 hourSulphur dioxide
3.8µg/m³Good · 1 hourCarbon monoxide
266µg/m³PM2.5 vs PM10 - what is the difference? → · Models and monitoring stations →
DAILY DATA · Chennai
Chennai - air pollution over recent days (2026-08-31 - 2026-10-22)
Concentrations of all available pollutants for this city.
PM2.5Lowest 3.72 2026-10-20Highest 22.37 2026-09-032026-08-31 - 2026-10-22
PM10Lowest 5.23 2026-10-19Highest 29.5 2026-09-032026-08-31 - 2026-10-22
O₃Lowest 52.79 2026-10-22Highest 111.17 2026-09-022026-08-31 - 2026-10-22
NO₂Lowest 3.47 2026-10-20Highest 15.39 2026-10-172026-08-31 - 2026-10-22
SO₂Lowest 2.5 2026-10-20Highest 17.52 2026-10-172026-08-31 - 2026-10-22
COLowest 206.83 2026-08-31Highest 450.71 2026-10-172026-08-31 - 2026-10-22
Scroll the chart or table sideways to see the full period.
| Pollutant | 2026-10-22 | 2026-10-21 | 2026-10-20 | 2026-10-19 | 2026-10-18 | 2026-10-17 | 2026-10-16 | 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 | 4.33 | 5.41 | 3.72 | 4 | 7.27 | 16.95 | 11.14 | 19.95 | 20.58 | 20.78 | 17.6 | 22.37 | 20.62 | 17.09 | 11.91 |
| PM10 | 5.83 | 7.35 | 5.38 | 5.23 | 8.2 | 17.78 | 12.75 | 25.75 | 25.6 | 26.35 | 23.28 | 29.5 | 26.64 | 22.52 | 17 |
| O₃ | 52.79 | 58.75 | 54.54 | 65.92 | 89.96 | 99.08 | 64.63 | 109.04 | 107 | 99.29 | 93.33 | 102.13 | 111.17 | 105.17 | 75.38 |
| NO₂ | 5.28 | 4.46 | 3.47 | 4.48 | 7.13 | 15.39 | 14.22 | 8.13 | 7.51 | 9.27 | 9.61 | 11.71 | 7.82 | 8.78 | 8.81 |
| SO₂ | 3.99 | 3.1 | 2.5 | 4 | 8.03 | 17.52 | 15.73 | 11.33 | 10.79 | 11.93 | 9.89 | 11.44 | 10.18 | 8.56 | 7.12 |
| CO | 271.13 | 288.71 | 250.71 | 275.67 | 367.25 | 450.71 | 424.79 | 267.54 | 244.63 | 271.29 | 294.54 | 265.29 | 248.38 | 262.29 | 206.83 |
A dot on the chart and a dash in the table indicate missing data. The latest day may be incomplete.
AIR QUALITY ARCHIVE · Chennai
Chennai - air pollution history (2015-12 - 2020-05)
Compare monthly particle and gas concentrations in the available archive.
PM2.5Lowest 9.12 2020-05Highest 597 2018-122015-12 - 2020-05
O₃Lowest 5.58 2020-03Highest 75.3 2019-022015-12 - 2020-05
NO₂Lowest 1.55 2020-04Highest 45.6 2018-052015-12 - 2020-05
SO₂Lowest 3.65 2019-09Highest 9.14 2018-052015-12 - 2020-05
COLowest 1 2019-02Highest 966 2018-112015-12 - 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 | 9.12 | 9.61 | 24.4 | 31.65 | 32.25 | 30.1 | 39.25 | 19.8 | 18.75 | 16.75 | 35.75 | 29.85 | 25.15 | 15.1 | 22.1 | 34.3 | 205 | 597 | 41 | 33.7 | 34.6 | 59.6 | 44.7 | 105 | 66.3 | 40.1 | 201 | 329 | 83.8 | 54 | 52 | 64.8 | 18.3 | 23 | 27.2 | 23.9 | 39.5 | 31.3 | 28.7 | 32.2 | 46.7 | 54.2 | 49.6 | 50.1 | 30.3 | 36.9 | 33.2 | 36.6 | 17.8 | 19.6 | 26.4 | 36.3 | 49.1 | 63.4 |
| O₃ | 11.8 | 11 | 5.58 | 19.7 | 12.1 | 22.6 | 17.1 | 15.3 | 15.1 | 20.4 | 33.5 | 41.1 | 17.7 | 15.8 | — | 75.3 | — | — | 21.1 | 31.5 | 30.8 | 9.18 | — | — | 33.5 | 26.1 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| NO₂ | 1.72 | 1.55 | 3.81 | 5.73 | 4.86 | 8.83 | 16.2 | 17.7 | 17.4 | 16.9 | 23.3 | 26.7 | 8.27 | 7.6 | — | 11.3 | — | — | 9.78 | 12.7 | 14.8 | 15 | — | — | 45.6 | 33.4 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| SO₂ | 3.98 | 7.4 | 6.39 | 6.03 | 5.28 | 4.92 | 4.53 | 4.7 | 3.65 | 3.83 | 3.69 | 4.08 | 4.68 | 4.58 | — | 4.48 | — | — | 4.23 | 6.16 | 4.19 | 4.26 | — | — | 9.14 | 4.06 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| CO | 744 | 747 | 665 | 875 | 845 | 454 | 525 | 793 | 724 | 724 | 767 | 1 | 826 | 843 | — | 1 | — | — | 966 | 779 | 659 | 648 | — | — | 925 | 779 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
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 2
AIR QUALITY ARCHIVE · US Diplomatic Post: Chennai
US Diplomatic Post: Chennai
Station code: US Diplomatic Post: Chennai
Monthly monitoring station data.
PM2.5Lowest 8.92 2020-04Highest 597 2018-122015-12 - 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 | 9.53 | 8.92 | 22 | 30.9 | 34.7 | 35 | 48.2 | 13.6 | 21.4 | 19.2 | 22.1 | 18.5 | 24.3 | 14.7 | 22.1 | 34.8 | 205 | 597 | — | — | 43.3 | 93.6 | 44.7 | 105 | 95.3 | 46.2 | 201 | 329 | 83.8 | 54 | 52 | 64.8 | 18.3 | 23 | 27.2 | 23.9 | 39.5 | 31.3 | 28.7 | 32.2 | 46.7 | 54.2 | 49.6 | 50.1 | 30.3 | 36.9 | 33.2 | 36.6 | 17.8 | 19.6 | 26.4 | 36.3 | 49.1 | 63.4 |
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 ↗StateAir_Chennai
AIR QUALITY ARCHIVE · Velachery Res. Area, Chennai - CPCB
Velachery Res. Area, Chennai - CPCB
Station code: Velachery Res. Area, Chennai - CPCB
Monthly monitoring station data.
PM2.5Lowest 8.71 2020-05Highest 49.4 2019-072018-04 - 2020-05
O₃Lowest 5.58 2020-03Highest 75.3 2019-022018-04 - 2020-05
NO₂Lowest 1.55 2020-04Highest 45.6 2018-052018-04 - 2020-05
SO₂Lowest 3.65 2019-09Highest 9.14 2018-052018-04 - 2020-05
COLowest 1 2019-02Highest 966 2018-112018-04 - 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 | 8.71 | 10.3 | 26.8 | 32.4 | 29.8 | 25.2 | 30.3 | 26 | 16.1 | 14.3 | 49.4 | 41.2 | 26 | 15.5 | — | 33.8 | — | — | 41 | 33.7 | 25.9 | 25.6 | — | — | 37.3 | 34 |
| O₃ | 11.8 | 11 | 5.58 | 19.7 | 12.1 | 22.6 | 17.1 | 15.3 | 15.1 | 20.4 | 33.5 | 41.1 | 17.7 | 15.8 | — | 75.3 | — | — | 21.1 | 31.5 | 30.8 | 9.18 | — | — | 33.5 | 26.1 |
| NO₂ | 1.72 | 1.55 | 3.81 | 5.73 | 4.86 | 8.83 | 16.2 | 17.7 | 17.4 | 16.9 | 23.3 | 26.7 | 8.27 | 7.6 | — | 11.3 | — | — | 9.78 | 12.7 | 14.8 | 15 | — | — | 45.6 | 33.4 |
| SO₂ | 3.98 | 7.4 | 6.39 | 6.03 | 5.28 | 4.92 | 4.53 | 4.7 | 3.65 | 3.83 | 3.69 | 4.08 | 4.68 | 4.58 | — | 4.48 | — | — | 4.23 | 6.16 | 4.19 | 4.26 | — | — | 9.14 | 4.06 |
| CO | 744 | 747 | 665 | 875 | 845 | 454 | 525 | 793 | 724 | 724 | 767 | 1 | 826 | 843 | — | 1 | — | — | 966 | 779 | 659 | 648 | — | — | 925 | 779 |
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 ↗caaqm
Air quality in nearby cities
All cities →Sri Lanka↗
Jaffna
PM2.53.6
PM103.9
µg/m³
PM2.5 · GoodNO₂ 5.1O₃ 57
October 23, 202606:30
Sri Lanka↗
Trincomalee
PM2.55.1
PM105.7
µg/m³
PM2.5 · FairNO₂ 12.8O₃ 22
October 23, 202606:30
India↗
Bengaluru Urban
PM2.59.1
PM109.5
µg/m³
PM2.5 · FairNO₂ 12.3O₃ 32
October 23, 202606:30
India↗
Hyderabad
PM2.548.8
PM1049.9
µg/m³
PM2.5 · ModerateNO₂ 12.4O₃ 68
October 23, 202606:30
India↗
Nagpur
PM2.526.5
PM1041.4
µg/m³
PM2.5 · ModerateNO₂ 12.4O₃ 55
October 23, 202606:30
India↗
Pune
PM2.537.7
PM1042
µg/m³
PM2.5 · ModerateNO₂ 10.6O₃ 72
October 23, 202606:30
India↗
Raigad Fort
PM2.536.9
PM1039
µg/m³
PM2.5 · ModerateNO₂ 19.1O₃ 42
October 23, 202606:30
India↗
Navi Mumbai
PM2.565.9
PM1070.8
µg/m³
PM2.5 · PoorNO₂ 29.8O₃ 26
October 23, 202606:30
India · air quality in other cities
WEATHER & SURROUNDINGS
Chennai · weather forecast
Daily maximum and minimum temperatures. Forecast point: 13.0878, 80.2785.
Scroll the forecast to see the following days.
Chennai · October 20, 2026: minimum temperature 27°C, maximum 31.1°C. Wind: 26.6 km/h. Humidity: 82%.
Full forecast: temperature, rainfall, wind and humidity
| Date | Day °C | Min °C | Max °C | Night °C | Rain mm | Wind m/s | Humidity % | Clouds % |
|---|---|---|---|---|---|---|---|---|
| 2026-10-20 | 28.8 | 27 | 31.1 | 28 | 5.4 | 7.4 | 82 | 100 |
| 2026-10-21 | 26.7 | 25.4 | 27.8 | 27.4 | 22.5 | 8.5 | 90 | 100 |
| 2026-10-22 | 27.9 | 26.3 | 30.3 | 28.1 | 28.2 | 4.7 | 85 | 90 |
| 2026-10-23 | 27 | 26.3 | 27.9 | 26.6 | 18 | 4.3 | 85 | 100 |
| 2026-10-24 | 29.1 | 25.6 | 30 | 28 | 1.9 | 5.8 | 67 | 98 |
| 2026-10-25 | 29.4 | 25.7 | 29.4 | 27.8 | 2.1 | 4.1 | 66 | 75 |
| 2026-10-26 | 31.1 | 26.1 | 32.2 | 26.8 | — | 6.4 | 46 | 100 |
| 2026-10-27 | 30.6 | 24.9 | 31.1 | 26.5 | 14.4 | 4.2 | 40 | 94 |
| 2026-10-28 | 31.9 | 25 | 31.9 | 27.3 | 5.9 | 4 | 33 | 17 |
| 2026-10-29 | 31.1 | 24.6 | 31.1 | 28 | 0.1 | 4.7 | 39 | 97 |
| 2026-10-30 | 32.3 | 25.5 | 32.3 | 28.7 | 0.3 | 5.8 | 43 | 100 |
| 2026-10-31 | 31.2 | 27 | 31.2 | 28 | 1.1 | 6.2 | 55 | 95 |
| 2026-11-01 | 29.9 | 26.8 | 29.9 | 27.4 | 5.3 | 5.4 | 59 | 66 |
| 2026-11-02 | 29.6 | 25.8 | 29.6 | 27.2 | — | 4.4 | 58 | 68 |
| 2026-11-03 | 30.1 | 25.6 | 30.1 | 27.1 | — | 6 | 62 | 56 |
| 2026-11-04 | 29.7 | 26.1 | 29.7 | 27.7 | 6.5 | 5 | 64 | 92 |
| 2026-11-05 | 30.1 | 26.8 | 30.1 | 27.3 | 5.6 | 5.2 | 63 | 100 |
| 2026-11-06 | 29.2 | 26.5 | 29.2 | 27.5 | 17.7 | 6.3 | 65 | 100 |
UV index by day · Chennai
City data.
Seek shade around midday. SPF 30+, sunglasses and a hat for longer stays.
0-2 low3-5 moderate6-7 high8-10 very high11+ extreme
Scroll the forecast to see the following days.
Chennai · October 22, 2026: UV index: 5.1 .
| Indicator | 2026-10-22 | 2026-10-23 | 2026-10-24 | 2026-10-25 | 2026-10-26 | 2026-10-27 | 2026-10-28 | 2026-10-29 | 2026-10-30 | 2026-10-31 | 2026-11-01 | 2026-11-02 | 2026-11-03 | 2026-11-04 | 2026-11-05 | 2026-11-06 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index | 5.1 | 6.2 | 1.8 | 5.2 | 8.1 | 4.6 | 6.6 | 7.6 | 7.8 | 7.6 | 7.7 | 8 | 8.1 | 7.8 | 8 | — |
AIR QUALITY QUESTIONS
Chennai · air pollution - questions and answers
What do the latest air quality data show for Chennai?
Chennai - latest available concentrations (October 23, 2026, 06:30 local time): PM2.5: 4.2 µg/m³, PM10: 5.1 µg/m³, O₃: 63 µg/m³, NO₂: 5.3 µg/m³, SO₂: 3.8 µg/m³, CO: 266 µg/m³. These are hourly CAMS model values for a point representing the city.
When was PM2.5 highest in Chennai over the past week?
The highest available daily mean PM2.5 was 16.9 µg/m³ (October 17, 2026). This comparison covers 7 days with data in the seven days before October 23, 2026. The day of the latest reading is excluded because it may be incomplete.
What period does the pollution history for Chennai cover?
Available monthly means cover 2015-12 - 2020-05. The tables include PM2.5, O₃, NO₂, SO₂, CO. 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 Chennai 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 Chennai?
For October 22, 2026, the forecast UV index is 5.1. The UV section also shows the following available days.
What wind speed is forecast for Chennai?
For October 20, 2026, forecast wind speed is 26.6 km/h. The weather table includes wind, temperature and other available parameters for subsequent days.
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.