Delhi's air quality remained in the "very poor" category for the fourth consecutive day on Wednesday, while the city recorded its second-coldest night of the season.

The minimum temperature dipped to 10.4 degrees Celsius, 0.1 notch above normal, according to the India Meteorological Department (IMD), which has also forecast a further drop to 9 degrees Celsius at night.

The coldest night of the season so far was recorded on November 21, when the temperature settled at 10.2 degrees Celsius.

Delhi's 24-hour average Air Quality Index (AQI) was recorded at 303 at 4 pm, a slight improvement from 343 the previous day, according to data from the Central Pollution Control Board (CPCB).

None of the 39 monitoring stations in the capital recorded the air quality in the "severe" category, similar to the trend observed on Tuesday.

The AQI had peaked at 419 on November 20, with subsequent readings of 371 the following day, 393 on Friday, 412 on Saturday and 318 on Sunday. An AQI between 301 and 400 is classified as "very poor" while levels above 400 are considered "severe".

The primary pollutants remained PM2.5 and PM10, with PM2.5 levels at 122 µg/m³ on Wednesday, down from 143 µg/m³ the previous day, and PM10 levels at 219 µg/m³, also lower than the 325 µg/m³ recorded on Tuesday.

These fine particles, especially PM2.5, pose significant health risks as these can penetrate deep into the lungs and enter the bloodstream.

The Centre's Decision Support System (DSS) for Air Quality Management attributed 24.6 per cent of Delhi's pollution on Wednesday to vehicular emissions, while stubble burning accounted for 5.8 per cent of the pollution on Tuesday.

The DSS provides daily estimates for vehicular emissions but the stubble-burning data is typically available the following day.

Meanwhile, the city's maximum (daytime) temperature was recorded at 27.3 degrees Celsius, a notch above normal, making it the third lowest of the season.

The coldest daytime temperature was recorded on November 19 at 23.5 degrees Celsius, followed by 27.2 degrees Celsius on both November 18 and November 23.

The humidity levels fluctuated between 93 per cent and 63 per cent during the day.

The weather department has forecast moderate conditions for Thursday, with the maximum and minimum temperatures expected to hover around 27 degrees Celsius and 9 degrees Celsius respectively.

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