<p>Delhi's air quality remained “very poor” on Thursday, and it is likely to remain so for the next two days.</p>.<p>The city's air quality index (AQI) was 342 at 9 am. The 24-hour average AQI was 373 on Wednesday. It was 367 on Tuesday, 318 on Monday and 268 on Sunday.</p>.<p>An AQI between zero and 50 is considered "good", 51 and 100 "satisfactory", 101 and 200 "moderate", 201 and 300 "poor", 301 and 400 "very poor", and 401 and 500 "severe".</p>.<p>The predominant wind direction will be northerly and the maximum wind speed 6 kmph on Thursday, according to the India Meteorological Department.</p>.<p>The minimum temperature was 8.2 degrees Celsius on Thursday and the maximum is expected to settle around 26 degrees Celsius, the weather department said.</p>.<p>The minimum temperature this season has remained 2-3 degree Celsius below normal in the absence of a cloud cover on most days, according to IMD officials.</p>.<p>Calm winds and low temperatures trap pollutants close to the ground, while favourable wind speed helps in their dispersion. </p>.<p> The central government's Air Quality Early Warning System for Delhi said air quality is likely to remain in the "very poor" category till Saturday.</p>.<p>There is a possibility of the air quality reaching the "severe" category between December 4 and December 7, it had said earlier.</p>.<p>The city's ventilation index -- a product of mixing depth and average wind speed – is likely to be 3,000 m2/s on Thursday.</p>.<p>Mixing depth is the vertical height in which pollutants are suspended in the air. It reduces on cold days with calm wind speed.</p>.<p>A ventilation index lower than 6,000 sqm/second, with the average wind speed less than 10 kmph, is unfavourable for dispersal of pollutants.</p>
<p>Delhi's air quality remained “very poor” on Thursday, and it is likely to remain so for the next two days.</p>.<p>The city's air quality index (AQI) was 342 at 9 am. The 24-hour average AQI was 373 on Wednesday. It was 367 on Tuesday, 318 on Monday and 268 on Sunday.</p>.<p>An AQI between zero and 50 is considered "good", 51 and 100 "satisfactory", 101 and 200 "moderate", 201 and 300 "poor", 301 and 400 "very poor", and 401 and 500 "severe".</p>.<p>The predominant wind direction will be northerly and the maximum wind speed 6 kmph on Thursday, according to the India Meteorological Department.</p>.<p>The minimum temperature was 8.2 degrees Celsius on Thursday and the maximum is expected to settle around 26 degrees Celsius, the weather department said.</p>.<p>The minimum temperature this season has remained 2-3 degree Celsius below normal in the absence of a cloud cover on most days, according to IMD officials.</p>.<p>Calm winds and low temperatures trap pollutants close to the ground, while favourable wind speed helps in their dispersion. </p>.<p> The central government's Air Quality Early Warning System for Delhi said air quality is likely to remain in the "very poor" category till Saturday.</p>.<p>There is a possibility of the air quality reaching the "severe" category between December 4 and December 7, it had said earlier.</p>.<p>The city's ventilation index -- a product of mixing depth and average wind speed – is likely to be 3,000 m2/s on Thursday.</p>.<p>Mixing depth is the vertical height in which pollutants are suspended in the air. It reduces on cold days with calm wind speed.</p>.<p>A ventilation index lower than 6,000 sqm/second, with the average wind speed less than 10 kmph, is unfavourable for dispersal of pollutants.</p>