Delhi braces for ‘severe’ AQI this week: What’s driving the worsening air quality?

Delhi AQI

Delhi’s air quality continued to remain in the ‘very poor’ category on Monday, with weak winds allowing pollutants to accumulate in the atmosphere.

According to data from the Sameer app developed by the Central Pollution Control Board (CPCB), the city recorded an overall Air Quality Index (AQI) of 324 at 6.05 am.

Experts have warned that pollution levels are expected to worsen further, with Delhi likely to slip into the ‘severe’ category for the first time this season on Tuesday.

Delhi AQI to worsen

The Indian Institute of Tropical Meteorology has forecast that slow wind speeds and dropping temperatures could push the city toward an air emergency. The Centre’s Air Quality Early Warning System also predicted that the AQI would remain in the ‘very poor’ range on Monday, turn ‘severe’ on Tuesday, and slightly improve back to ‘very poor’ levels by Wednesday.

On Sunday, Delhi recorded an AQI of 366, still in the ‘very poor’ range. Several nearby cities in the National Capital Region (NCR) also reported similarly poor air, with Noida recording 311, Ghaziabad 334, and Gurugram 304.

Most polluted fortnight ahead

Meteorologists said that while Delhi has seen slightly higher-than-normal temperatures so far, which have helped limit the pollution buildup, the coming days are likely to see calm winds and lower temperatures, which will trap pollutants near the surface.

On Sunday, Delhi’s minimum temperature was 16.8°C, 1.5 degrees above normal, while the maximum stood at 30.7°C. Notably, 18 of the city’s 39 monitoring stations reported ‘severe’ AQI readings (above 400) on Sunday morning, which later dropped to ‘very poor’ levels by evening.

What is causing the spike?

The Delhi Pollution Control Committee (DPCC) noted that the first half of November, between November 1 and 15, has historically been the most polluted period in the capital. Data from 2018 to 2023 shows an average AQI of 371 during this fortnight, coinciding with stubble burning in neighbouring states, post-festival traffic, and weather conditions that trap smog.

Experts also warned that paddy stubble burning in Punjab is likely to rise in the coming days as farmers speed up post-harvest field clearing after delays caused by floods and heavy rains earlier this year.

Mahesh Palawat, Vice President (Meteorology and Climate Change) at Skymet, said that light winds briefly improved the air quality during the day but turned westerly and northwesterly later, directions that can carry stubble smoke from Punjab and Haryana to Delhi.

“A western disturbance is expected in north India between Nov 4 and 5, but it is unlikely to bring rain, only some cloudiness. As a result, Delhi’s air quality may worsen further before any relief is expected,” Palawat was quoted by TOI as saying.