Air quality
Air quality in Chennai today
Updated
Moderate (US AQI 69) Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors. Model estimate for Sun, Oct 25, 11:30 pm (18:00 UTC).
Live AQI, PM2.5, PM10 and ozone for Chennai, Tamil Nadu, India, with a 48-hour forecast and the best time to be outside.
- US AQI now
- 69 Moderate
- PM2.5
- 40 µg/m³ 2.7× WHO 24-h guideline
- PM10
- 48 µg/m³
- Ozone
- 113 µg/m³
- Dominant pollutant
- PM2.5 sub-index 69
- Best hour today
- 6:30 am AQI 89
- European AQI
- 54
Air quality in Chennai right now
Right now the modelled US Air Quality Index for Chennai, Tamil Nadu, India is 69, which falls in the "Moderate" band (up to 100). Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors.
The index is driven mainly by PM2.5, whose own sub-index is 69. Fine and coarse particles come from traffic, heating, industry, dust and smoke; they build up on calm nights and clear when wind or rain arrives.
PM2.5 is 40 µg/m³, 2.7 times the WHO 24-hour guideline of 15 µg/m³; PM10 is 48 µg/m³ against a guideline of 45; ozone is 113 µg/m³ (above the WHO 8-hour level of 100); nitrogen dioxide is 5.5 µg/m³ (below the 24-hour guideline of 25).
Also this hour: carbon monoxide 319 µg/m³.
Chennai AQI forecast: next 48 hours
Over the next 24 hours the AQI is forecast to range from 69 around Sun 11:30 pm to 139 around Mon 4:30 pm, from "Moderate" at best to "Unhealthy for Sensitive Groups" at worst.
The following day is expected to be worse, averaging about 143 against 110 for the next 24 hours.
| Local time (Asia/Kolkata) | US AQI | Category | PM2.5 µg/m³ | PM10 µg/m³ | Ozone µg/m³ |
|---|---|---|---|---|---|
| Sun 11:30 pm | 69 | Moderate | 40 | 48 | 113 |
| Mon 2:30 am | 77 | Moderate | 42.7 | 53 | 128 |
| Mon 5:30 am | 86 | Moderate | 48.8 | 59 | 144 |
| Mon 8:30 am | 98 | Moderate | 52 | 62 | 157 |
| Mon 11:30 am | 121 | Unhealthy for Sensitive Groups | 54.1 | 65 | 164 |
| Mon 2:30 pm | 136 | Unhealthy for Sensitive Groups | 50.6 | 60 | 158 |
| Mon 5:30 pm | 138 | Unhealthy for Sensitive Groups | 50.1 | 60 | 152 |
| Mon 8:30 pm | 133 | Unhealthy for Sensitive Groups | 50.4 | 60 | 161 |
| Mon 11:30 pm | 136 | Unhealthy for Sensitive Groups | 50.2 | 57 | 171 |
| Tue 2:30 am | 147 | Unhealthy for Sensitive Groups | 47.7 | 55 | 170 |
| Tue 5:30 am | 152 | Unhealthy | 51.5 | 57 | 156 |
| Tue 8:30 am | 142 | Unhealthy for Sensitive Groups | 58.1 | 63 | 147 |
| Tue 11:30 am | 140 | Unhealthy for Sensitive Groups | 44.6 | 49 | 184 |
| Tue 2:30 pm | 149 | Unhealthy for Sensitive Groups | 32.8 | 36 | 175 |
| Tue 5:30 pm | 153 | Unhealthy | 31.5 | 34 | 116 |
| Tue 8:30 pm | 125 | Unhealthy for Sensitive Groups | 42 | 45 | 108 |
| Tue 11:30 pm | 123 | Unhealthy for Sensitive Groups | 49.8 | 53 | 46 |
Every third hour of the CAMS forecast via Open-Meteo. US AQI uses rolling averages (24 h for particles, 8 h for ozone), so it moves more slowly than the hourly concentrations.
Best time to be outside in Chennai today
Between 6 am and 9 pm local time, the cleanest air today is forecast around 6:30 am (AQI 89, Moderate) and the worst around 4:30 pm (AQI 139). That is a swing of 50 points, so a run or walk around 6:30 am is noticeably better.
Chennai vs the rest of India
Across 260 India cities we track, the average US AQI right now is 116 (Unhealthy for Sensitive Groups). Chennai at 69 is 47 points cleaner than average.
It ranks 38 of 260 from cleanest to most polluted; the cleanest is Dindigul (26) and the most polluted Karnāl (346).
For context, the median across 3,909 cities worldwide is 57.
Air quality in cities near Chennai
| City | Distance | US AQI | Category | PM2.5 µg/m³ |
|---|---|---|---|---|
| Ambattur | 13 km | 69 | Moderate | 40 |
| Avadi | 19 km | 70 | Moderate | 37.7 |
| Pallāvaram | 19 km | 69 | Moderate | 40 |
| Tambaram | 24 km | 69 | Moderate | 40 |
| Rānipet | 104 km | 58 | Moderate | 30.3 |
| Tirupati | 111 km | 63 | Moderate | 36.8 |
| Vellore | 126 km | 58 | Moderate | 30.3 |
| Puducherry | 137 km | 30 | Good | 5.8 |
Model vs measured
We found no measured PM2.5 sensor cell within 25 km of Chennai, so the numbers on this page are model estimates. Models capture regional pollution well but can miss very local sources such as a busy road or a nearby fire.
Advice for sensitive groups
At 69, most people are fine outdoors. If you are unusually sensitive to PM2.5, keep long or intense workouts to the cleaner hours shown above.
What the US AQI numbers mean
| US AQI | Category | What it means |
|---|---|---|
| 0-50 | Good | Air quality is satisfactory and poses little or no risk; a good time for outdoor activity. |
| 51-100 | Moderate | Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors. |
| 101-150 | Unhealthy for Sensitive Groups | People with heart or lung disease, older adults, children and teens should cut back on prolonged or heavy exertion outdoors. |
| 151-200 | Unhealthy | Everyone should reduce prolonged or heavy exertion outdoors; sensitive groups should avoid it and keep windows closed. |
| 201-300 | Very Unhealthy | Health alert: everyone should avoid prolonged or heavy exertion outdoors, and sensitive groups should stay indoors. |
| 301-500 | Hazardous | Emergency conditions: everyone should avoid all outdoor physical activity and stay indoors with filtered air if possible. The scale tops out at 500; heavier dust or smoke is shown as 500. |
Values on this page are modelled by CAMS (Copernicus) and served by Open-Meteo; they are estimates for the area around the city centre, not readings from an official monitor.
Nearby cities
More for Chennai
Air quality elsewhere
Data: Open-Meteo Air Quality API, Copernicus Atmosphere Monitoring Service (CAMS).