Air quality in Delhi remains in the very poor category

On Friday morning, Delhi’s air quality remained in the very poor category, and it was expected to remain so throughout the week.

At 7 a.m., the hourly air quality index (AQI) was 345, according to the Central Pollution Control Board. The average 24-hour AQI on Thursday was 354.

An AQI of zero to fifty is considered good, 51 to one hundred satisfactory, 101 to two hundred moderate, 201 to 300 poor, 301 to 400 very poor, and 401 to 500 severe.

Fine particles (size 2.5 micrometre) contributed 52% of PM10, according to the government’s monitoring agency System of Air Quality and Weather Forecasting and Research (Safar). The contribution of stubble fires (1082) in the northwest region to Delhi’s PM2.5 was minimal.

Winds at the transport level (750 – 1000 m) were weak and mostly blowing from the northwest, according to Safar. “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 predicted to be 15 degrees Celsius, with a maximum temperature of 32 degrees Celsius.

On Thursday, the low temperature was 15 degrees Celsius and the high temperature was 31.9 degrees Celsius, which was two degrees above normal.