Coldest morning so far this season, AQI may worsen in Delhi

Temperatures are expected to remain in a similar range over the next few days, even as the pollution is likely to worsen by Saturday morning

Temperatures continued to dip in the region on Friday, as Delhi recorded the season’s lowest minimum at 14 degrees Celsius in the morning, a drop which coincided with a season high farm-fire contribution of 20% percent to the city’s pollution levels, worsening its air quality further.

Delhi recorded a 24-hour average air quality index (AQI) reading of 283 (poor) on Friday, (Amal KS/Hindustan Times)

Temperatures are expected to remain in a similar range over the next few days, even as the pollution is likely to worsen by Saturday morning, possibly dropping into the ‘very poor’ zone, agencies forecast.

Delhi recorded a 24-hour average air quality index (AQI) reading of 283 (poor) on Friday, according to the Central Pollution Control Board’s (CPCB) 4pm bulletin, with at least 11 monitoring stations hitting the ‘very poor’ category in the evening.

The Capital logged an AQI of 268 (also categorised as ‘poor’) on Thursday’s bulletin.

According to the System of Air Quality and Weather Forecasting and Research (Safar), a central government forecasting body, the number of farm fires has more than doubled in the northern plains over the last 24 hours, with 1,112 blazes recorded on Friday, more than double Thursday’s count of 502.

Smoke from the fires made up 20% of Delhi’s air on Friday, up from 19% a day earlier.

“The air quality is likely to deteriorate further during the day until early Saturday morning and then likely to improve marginally from Saturday evening onwards. However, it will still remain in the lower end of the ‘very poor’ or higher end of the ‘poor’ category, despite slightly improved ventilation co-efficient,” SAFAR said on Friday.

Delhi’s overall AQI has gradually been on the rise this week, spiking from a reading of 82 (satisfactory) on Monday to 139 (moderate) on Tuesday, 268 (poor) by Thursday and till 283 (poor) in the last 24 hours.

The CPCB classifies an AQI between 201 and 300 as ‘poor’ and over 300 as ‘very poor’. At least 11 stations were in the ‘very poor’ range on Friday evening, including Wazirpur, Bawana, Shadipur, Mundka, Anand Vihar, Dwarka, Jahangirpuri and Alipur, among others. The Shadipur station recorded Delhi’s worst AQI, at 390.

Meanwhile, the maximum temperature on Friday was 30.4°C – a notch below normal. Safdarjung — Delhi’s base station — recorded a minimum of 14°C, but Aya Nagar was the city’s coldest spot, hitting a low of 13.4°C. The lowest minimum so far this season at Safdarjung before this was 14.6°C on Thursday.

An official from the India Meteorological Department (IMD) said that the wind speed is expected to increase marginally from Saturday, but will have little impact on the city’s pollution levels.

“Wind speeds will increase from around 5kmph to around 10-12kmph by Sunday. However, wind direction will remain northwesterly and the impact of stubble burning is expected to continue,” the official said.

The IMD forecasts a maximum and minimum of 29°C and 14°C respectively on Saturday, with shallow mist in the morning.