Overall air quality in Delhi on Thursday remained 'very poor' as the Met said the current cold wave conditions prevailing over northwest India may not allow it to improve.
"The minimum temperature is likely to fall in Delhi during the next few days resulting in additional moisture in the air, mainly due to a drastic drop in mercury and ground frost conditions over some parts of northwest India.
"Hence, air quality will remain in the very poor zone," System of Air Quality and Weather Forecasting and Research (SAFAR) said.
According to the India Meteorological Department (IMD), night temperatures over many parts of Delhi fell by 2-3 degrees Celsius, reaching 4 degrees Celsius on Wednesday night - the coldest recorded temperature so far this season.
Moderate fog brought down the visibility to 300 metres in the city.
The overall Air Quality Index (AQI) of Delhi stood at 369 (very poor). However, some areas of Delhi-National Capital Region fell to 'severe' level.
As per SAFAR data, Delhi University was at 497, Pitampura 456, Noida 420, Dhirpur 437, and Mathura Road was at 447 - all at 'severe' levels.
The average concentration of particulate matter (PM2.5 and PM10) in Delhi were 146 and 288 microgrammes per cubic metres, respectively. Across NCR, it was between 142 and 281 units.
IANS
