Despite a complete ban on firecrackers and stern warnings from the Supreme Court, Delhi experienced a persistently 'poor' air quality on Monday morning following Diwali celebrations. The PM 2.5 levels surged to nearly 30 times the permissible hourly standards for ultrafine particles, particularly spiking between midnight and 2 am. This concentration is anticipated to gradually shift Delhi's average air quality index (AQI) into the 'very poor' category later in the day.
As of 7 am this morning, Delhi's 24-hour average AQI registered at 275 (poor), marking an increase from Sunday's 4 pm average reading of 218 (poor). The AQI has been on a gradual rise since Sunday evening when firecracker emissions began. The 24-hour rolling average climbed to 225 (poor) at 9 pm, 240 (poor) at midnight, and 261 (poor) at 5 am.
Delhi Pollution Control Committee (DPCC) data revealed an alarming hourly PM 2.5 concentration, reaching as high as 1,856 micrograms per cubic meter at east Delhi's Patparganj – approximately 31 times the national 24-hour PM 2.5 standard of 60 micrograms per cubic meter. Subsequent peaks were recorded at 1,792 micrograms per cubic meter at Jahangirpuri (11 pm) and 1,785 micrograms per cubic meter at Nehru Nagar.
Most stations documented their peak PM 2.5 levels around 1 am, with levels gradually subsiding from 2 am onwards.
India Meteorological Department (IMD) forecasts indicated predominantly calm winds in the early hours of Monday, likely trapping pollutants in the atmosphere until around noon. Subsequently, winds of 4-6 km/hr are expected to gradually disperse pollutants. Wind speeds during Diwali reached up to 10 km/hr, and on Saturday, a day after light showers, they peaked at 18 km/hr. This contributed significantly to Delhi's lower baseline pollution levels leading up to Diwali.
Comparatively, last year, Delhi recorded an average AQI of 302 (very poor) on November 5 – the day after Diwali, marking the lowest post-festival AQI in the last seven years. On Diwali day, the average AQI was 312 (very poor), with Delhi benefiting from strong winds that aided in dispersing firecracker smoke.
An IMD official stated, "Winds are expected to be around 4-6 km/hr during the day on both Monday and Tuesday. The wind direction is expected to be northwesterly during this period."
Additionally, Delhi experienced a dip in mercury on Sunday, recording a minimum temperature of 12.4 degrees Celsius – a degree below normal and the lowest this season. The minimum temperature is projected to hover around 13 degrees Celsius today and tomorrow.
