Delhi's minimum temperature settled at 7.8 degrees Celsius, a notch above normal, on Wednesday, the India Meteorological Department (IMD) said.

A fresh Western Disturbance will start affecting the Western Himalayan region Friday onwards. As a result, the mercury is likely to drop to 4 degrees Celsius by Monday, an IMD official said.

The city's air quality improved slightly on Wednesday morning on the back of strong surface winds.

The AQI stood at 308 at 9 am.

Delhi's air quality had turned severe on Tuesday, the sixth time this month, due to low wind speed and high moisture levels.

The city's 24-hour AQI was 404 on Tuesday, 372 on Monday and 347 on Sunday. Before that, Delhi's air quality remained in the severe zone for three consecutive days.

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.