Delhi's air quality worsened to the 'severe plus' for the first time in the season as the Air Quality Index (AQI) surged to 457. Earlier, in the morning people in the national capital woke up to dense smog on Sunday morning, with air quality remaining in the ' severe' category. But, after a few hours, according to the System of Air Quality and Weather
Forecasting and Research (SAFAR), the city's overall Air Quality Index (AQI) was recorded at a 'severe-plus 457, triggering grave health concerns.
According to AQI classifications, a 0-50 range is considered "good," 51-100 "satisfactory," 101-200 "moderate," 201-300 "poor," 301-400 "very poor," and 401-500 "severe/severe-plus".