Delhi's AQI improves to 'very poor' category on Christmas Day

Delhi's air quality index improved after remaining in the ‘severe’ category for four days. Despite bad air quality, which led to reduced visibility, the flight operations remain normal at Delhi airport. Light rain is likely in parts of north India from December 27, which may improve AQI a bit.

The pollution level in national capital Delhi improved marginally on Christmas Day (December 25), but still remained in ‘very poor’ category. Delhi’s air quality has been oscillating between ‘very poor’ and ‘severe’ over the last few weeks due to a combination of factors.

According to SAFAR data, Delhi's air quality index improved marginally on Saturday morning. (Sachin Khanna/HT File Photo)

The air quality index (AQI) recorded a reading of 398 on Saturday morning, according to the System of Air Quality and Weather Forecasting And Research (SAFAR), as per news agency ANI.

The morning was also cold, with the temperature settling at 7 degrees Celsius, a notch below normal, according to the India Meteorological Department (IMD).

On Friday, the AQI in Delhi was ‘severe’, with a recording of 433 at 7am, as per CPCB data. The average 24-hour AQI was 423 on Thursday. On Wednesday, the AQI was 407 and 402 on Tuesday.

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".

Despite bad air quality, which led to reduced visibility, the flight operations remain normal at Delhi airport.

In Delhi’s neighbours Noida and Gurugram, in the national capital region (NCR), the AQI was in ‘severe’ category. The AQI in Noida was at 491, while in Gurugram, it stood at 365, according to news agency ANI.

Weather experts said the slowing down of winds due to a western disturbance affecting northwest India is leading to accumulation of pollutants, and high moisture content in the air makes pollutants heavier, making dispersion difficult.

Light rain is likely in the plains of north India between December 27 and December 29, which may improve the air quality a bit.

On Saturday, Delhi is expected to see mainly clear sky, and the maximum temperature may reach up to 23 degrees Celsius, the weather department said.

On Monday, the CAQM lifted restrictions on construction and demolition activities in the Delhi-NCR and entry of trucks into the national capital in view of an improvement in the air quality and "favourable" meteorological forecast.

However, Delhi's air quality turned 'severe' the next day.