Delhi’s air quality remains in very poor category

According to the Central Pollution Control Board, the hourly air quality index (AQI) was 345 at 7am while the average 24-hour AQI was 354 on Thursday

Delhi’s air quality remained in the very poor category on Friday morning and was likely to continue to be the same this week.

The minimum temperature was expected to be 15 degrees Celsius. (PTI)

According to the Central Pollution Control Board, the hourly air quality index (AQI) was 345 at 7am. On Thursday, the average 24-hour AQI was 354.

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.

The government’s monitoring agency System of Air Quality and Weather Forecasting and Research (Safar) said fine particles (size < 2.5 micrometer) contributed ~ 52% to PM10. It added the share of stubble fires (1082) in the northwest region to Delhi’s PM2.5 was meagre.

Safar said winds at the transport level (750 – 1000 m) were weak and blowing mostly from the northwest direction. “Local surface winds are calm to 8 km/h...for next three days that cause weak dispersion of pollutants. Peak mixing layer height’ during daytime (~1.0 – 1.5 km) leads to moderate vertical dispersion of pollutants.”

The minimum temperature was expected to be 15 degrees Celsius and the maximum of 32 degrees Celsius.

On Thursday, the minimum temperature was 15 degrees Celsius, and the maximum of 31.9 degrees Celsius, two degrees above normal.