Delhi residents endured the fourth consecutive day of 'poor' air quality on Thursday, with indicators at 13 monitoring stations across the city being in the 'red zone', up from two the day before.

The 13 stations -- Ashok Vihar, Dwarka Sector 8, Patparganj, Punjabi Bagh, Rohini, Bawana, Burari, Jahangirpuri, Mundka, Narela, Okhla Phase 2, Shadipur, and Vivek Vihar -- recorded readings above 300, according to the Central Pollution Control Board (CPCB).

The overall air quality remained in the 'poor' category for the fourth consecutive day, with an average 24-hour reading of 285 recorded at 4 pm.

The city witnessed a cloudy sky through the day with a maximum temperature of 36.2 degrees Celsius, three notches above normal, according to the weather department.

On Thursday, relative humidity fluctuated between 91 percent and 55 percent, with the minimum temperature settling at 20.3 degrees Celsius, a notch above the season's average.

The IMD has forecast a mainly clear sky for Friday, with maximum and minimum temperatures expected to hover around 35 degrees Celsius and 18 degrees Celsius, respectively.

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".

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