The air quality index (AQI) in the national capital was close to 'severe' level on an overcast Wednesday morning while the minimum temperature settled at 25.4 degrees Celsius, a notch below the season's average.
Central Pollution Control Board data showed Delhi's AQI at 395 ('very poor') at 9 am, just five notches short of touching 'severe' level. An AQI between zero and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor', and 401 and 500 'severe'.
The weather office has predicted dust storm or thunderstorm during the day while the maximum temperature is likely to settle around 40 degrees Celsius.
The relative humidity at 8.30 am was recorded at 47 per cent, the India Meteorological Department said.
Thunderstorms with light to moderate rain is likely in isolated places of north Delhi, Gohana, Gannaur, Sonipat, Rohtak and Kharkhoda of Haryana, and Baraut, Bagpat and Khekra of Uttar Pradesh, the weather office said.
-With PTI Input