The minimum temperature in Delhi dipped to 8 degrees Celsius on Wednesday from 9.1 degrees a day ago.
The city also recorded a high of 24 degrees Celsius.
Weather experts said the minimum temperature is likely to drop to 7 degrees Celsius by Friday as high-velocity, cold and dry northwesterly winds continue to blow from higher hills.
Falling temperatures and an expected dip in wind speed are likely to push the pollution levels up by Friday.
On Wednesday, the city's air quality index read 280 at 9.30 am, while in Ghaziabad it read 333, in Gurgaon it was 266 and in Greater Noida it was 286.
The IMD has forecast a partly cloudy sky.
On Monday, the mercury had also touched 8 degrees Celsius, the season's lowest.