The minimum temperature in Delhi is expected to drop to 13 degrees Celsius by next week owing to cold north-westerly winds from the Himalayas, government agencies said on Wednesday. An increase in stubble burning in Haryana and Punjab is likely to push Delhi's air quality to the "poor" zone on Wednesday, they said.
The India Meteorological Department (IMD) said the Safdarjung Observatory, considered the official marker for the city, recorded a minimum temperature of 14.6 degrees Celsius on Wednesday morning, which was two notches below normal.
The maximum temperature is likely to settle around 28 degrees Celsius.
The city had on Tuesday recorded a maximum temperature of 28 degrees Celsius, four notches below normal.
According to an IMD forecast, the minimum temperature is likely to dip to 13 degrees Celsius by November 1.
Authorities said Delhi's air quality may get pushed to the "poor" zone on Wednesday and to the very poor category over the next five days because of an increase in stubble burning.
According to the Central Pollution Control Board, Delhi's 24-hour average air quality index (AQI) stood at 139 on Tuesday. It was 82 on Monday and 160 on Sunday.
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 Ministry of Earth Sciences' forecast agency SAFAR said emission from farm fires is expected to increase due to dry weather over north India in the next three days and Delhi's PM2.5 pollution level is likely to rise.
"Drier conditions tend to increase PM10. Thus, overall AQI is likely to degrade to the 'poor' category over the next three days," it said.
According to the Ministry of Earth Sciences' Air Quality Early Warning System for Delhi, the share of smoke from stubble burning in the national capital's pollution is likely to rise to 20 per cent on Wednesday.
It said 329 crop residue burning fire points were observed in Punjab, 175 in Haryana and 41 in UP on Tuesday.
(With inputs from PTI)