Delhi Air Quality Index: Delhi's 24-hour Air Quality Index was 400. (File)
The maximum temperature in Delhi settled one notch above the normal at 27.8 degrees Celsius on Thursday, while the city's air quality index (AQI) turned 'severe' from 'very poor' in the morning.
The weather department has predicted 'shallow fog' for the next four days.
It was a cold Thursday morning in Delhi as it recorded a minimum temperature of 9.7 degrees Celsius, two notches below the season's average, the IMD said.
At 402, the AQI was recorded in the 'severe' category' at 7 pm on Thursday, according to the real-time data of the Central Pollution Control Board (CPCB). The AQI recorded at 9 am was 390.
The city's 24-hour AQI was 400.
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.
Neighbouring Faridabad (405) too recorded its AQI in the 'severe' category, while the air quality of Ghaziabad (355), Gurugram (350), Greater Noida (340) and Noida (340) continued to be under the 'very poor' category.
According to MeT, the humidity level was recorded at 58 per cent at 5.30 pm on Thursday.