11 trains delayed as cold wave grips Delhi

As many as 11 trains coming into Delhi were delayed on Friday owing to the dense fog blanketing northern India.

In addition to the extreme weather conditions, air quality continued to remain very poor.

According to System of Air Quality and Weather Forecasting And Research (SAFAR), the overall Air Quality Index (AQI) of the national capital was recorded at 351 till 8.00 am, which falls in the ' very poor' category.

According to the AQI data, major pollutants PM 2.5 was at 186 and PM 10 was at 298, in 'Poor' and 'Very Poor' category respectively.

At Mathura road, major pollutant PM 2.5 was detected at 369 (very poor). In Lodhi road and Ayanagar area, the air quality dipped to the 'very poor' category at 328 and 308, respectively.

AQI in the range of 51 to 100 is considered as satisfactory, 101-200 is moderate, 201-300 falls under the category of poor, 300-400 is considered 'very poor' and 401-500 falls under the 'hazardous' category.