Fog reduces visibility, delays trains in Delhi; air quality remains ‘severe’

Delhi on Sunday continued to witness a foggy morning with reduced visibility, with the air quality in ‘severe’ category. According to the System of Air Quality and Weather Forecasting and Research (SAFAR), the overall Air Quality Index (AQI) stood at 428 today. An AQI between 0-50 is marked good, 51-100 is satisfactory, 101- 200 is moderate, 201- 300 is poor, 301-400 is very poor and 401-500 is considered severe.