The maximum temperature in Delhi settled three notches below the normal at 28.5 degrees Celsius on Thursday, the India Meteorological Department (IMD) said.
The weather office predicted mainly clear sky and colder days and nights for next two days.
The city witnessed a cold Thursday morning as it recorded a minimum temperature of 14.6 degrees Celsius, one notch below the season''s average, the IMD said.
According to the MeT department, the humidity level was recorded at 50 per cent at 5.30 pm on Thursday.
The days and nights will become colder as temperatures are likely to drop further in coming days due to north-westerly winds from the Himalayas, weather officials said.
The minimum temperature on Wednesday was 14.6 degrees Celsius, which was the lowest this season so far.
The air quality index (AQI) was recorded in the poor category at 269 at 6 pm on Thursday, real-time data of the Central Pollution Control Board showed.
The air quality stood at 232 on Wednesday while it was 139 on Tuesday, 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 the national capital's air quality will deteriorate further and enter "very poor" category on Friday.
It said a rise in farm fires over north India in the next three days will increase Delhi's PM2.5 pollution level.
The share of smoke from stubble burning in the city's pollution rose to 16 per cent on Wednesday.