Delhi's Air Quality Nears 'Poor' Category As Cold Winds Bring Winter Chill

Delhi's air quality inched closer to the ‘poor' category on Friday, with forecasts suggesting similar conditions could persist over the weekend. Meanwhile, residents experienced a winter chill during the early hours and evenings with cold winds, while the daytime remained mostly clear and sunny. Meanwhile, residents experienced a winter chill during the early hours and evenings with cold winds, while the daytime remained mostly clear and sunny.

The temperature at night was recorded at 8.5 degrees Celsius, a notch below normal, similar to that on Thursday.

The 24-hour average air quality index of the city was recorded at 197 at 4 pm, registering a slight increase from 165 on Thursday.

Experts have said the air quality in Delhi may deteriorate after the weekend, likely slipping into the ‘poor' category as wind direction and speed change.

Mahesh Palawat of Skymet Weather Services said that currently, the wind is dispersing pollutants effectively, with speeds ranging between 10 and 15 kmph and occasionally reaching 15 to 18 kmph.

However, he added that the air quality is expected to remain stable over the next few days but may decline to the ‘poor' category on Monday, due to changes in wind patterns and weather conditions.

He further noted that southeasterly winds are expected to approach after this, which could help improve air quality, bringing it back to the ‘moderate' category.

The air quality in the national capital began deteriorating on Oct. 30, entering the ‘very poor' category.

Throughout November, residents endured toxic air. However, with the onset of December, air quality showed signs of improvement due to stronger winds. Starting Dec. 1, the AQI improved to the ‘poor' category and has continued to get better since.

Of the 37 air quality monitoring stations in the city, 14 reported air quality in the ‘poor' category on Friday, while the remaining stations recorded ‘moderate' air quality, according to the Sameer app.

The Central Pollution Control Board classifies AQI levels between 0 and 50 as ‘good,' 51 to 100 as ‘satisfactory,' 101 to 200 as ‘moderate,' 201 to 300 as ‘poor,' 301 to 400 as ‘very poor,' and above 400 as ‘severe.' On Friday, the primary pollutants were PM2.5, PM10, and O3, with PM2.5 levels recorded at 73.7 µg/m³ at 3 pm and PM10 levels at 157.2 µg/m³ during the same time. Experts warn that these fine particles pose significant health risks as they can penetrate deep into the lungs and enter the bloodstream.

The Decision Support System, the primary tool used to assess and estimate the sources of pollution in Delhi, has not been updated since Friday. The latest data available on its website is from November 26 to November 29, with no updates for the last six days.

A Commission for Air Quality Management official stated that the DSS is still in the development phase and has not been fully commissioned yet.

"An evaluation committee reviewed the system and found that its data and accuracy were not in line with the terms of reference set for the model. It was also observed that some of the data or the emissions inventory being used was outdated,” the official said on the condition of anonymity.

The DSS will resume sharing data once the necessary changes are implemented.

The Air Quality Early Warning System for Delhi has forecast that air quality is likely to remain in the ‘poor' category over the weekend.

According to the India Meteorological Department, the maximum daytime temperature was recorded at 25.1 degrees Celsius, 0.2 degrees below normal.

Palawat said that a new western disturbance is approaching, which will also impact the capital. Some rain is expected, and temperatures are likely to drop from Dec. 9.

Humidity levels fluctuated between 67% and 50% during the day.

The IMD has forecast shallow fog conditions for Sunday, with maximum and minimum temperatures expected to hover around 26 degrees Celsius and seven degrees Celsius, respectively.