Delhi logs ‘severe’ air quality index despite overnight drizzle

Delhi clocked a 24-hour average AQI of 409 at 4pm, significantly worse than 368 (very poor) a day ago and 333 on Monday, according to data from the CPCB.

Pollution levels in Delhi worsened into the “severe” zone of the air quality index (AQI) on Wednesday, as calm winds exacerbated the effect of local emissions, even as the city’s night temperature inched up by more than a degree.

The pollution spike came despite a jump in temperatures. Delhi’s minimum rose from 6.9°C on Tuesday to 8.3°C on Wednesday – a degree above normal. (Viipin Kumar/ HT Photo)

Particulate pollutants in the air also mingled with the fog to form a sheet of smog that tinted the entire city for large parts of the day, pinching the visibility to 200m and hampering flight schedules once again.

Delhi clocked a 24-hour average AQI of 409 at 4pm, significantly worse than 368 (very poor) a day ago and 333 on Monday, according to data from the Central Pollution Control Board (CPCB). Wednesday’s AQI was the worst since 447 on January 14.

Such noxious air leaves even healthy people susceptible to serious long-term illnesses, while the outlook is even more bleak for children, the elderly and people with existing illnesses.

Still, the Commission for Air Quality Management (CAQM) in the National Capital Region (NCR) resisted imposing curbs under Stage 3 of the Graded Response Action Plan, citing forecasts that the air will get cleaner over the next few days.

The pollution spike came despite a jump in temperatures. Delhi’s minimum rose from 6.9°C on Tuesday to 8.3°C on Wednesday – a degree above normal. The maximum temperature, however, fell marginally, from 19.5°C to 18.3°C on Wednesday, three below normal.

Read Here: Winter chills continue in north India; 150 flights, 28 trains delayed in Delhi

The weather station in Safdarjung also recorded “trace” rainfall early in the morning.

At the Indira Gandhi International (IGI) Airport, the smog led to over 50 flights being delayed. However, no flights were diverted or cancelled. The Northern Railway, meanwhile, said at least 24 trains were delayed by over one hour on Wednesday.

To be sure, the hazardous pollution levels also mark the third, and usually final, phase of Delhi’s tryst with torrid winter air.

The city usually goes through three fortnights where the AQI is routinely in the severe zone: The first half of November, the second half of December, and then mid-January. During the first phase, the toxicity is fuelled largely by smoke from farm stubble fires in Punjab. The second and third phases are, however, down largely to local sources of pollution like vehicular and industrial emissions, which are in turn worsened by nearly still winds and dipping temperatures.

IMD also issued a yellow alert for Thursday, forecasting moderate to dense fog to prevail across the city, adding that the maximum and minimum will hover around 19 and 7 °C respectively.