AQI back to ‘moderate’ on windy day in Delhi

Delhi’s minimum saw a sharp rise on Saturday, as the city logged the day’s low at 13.4 degrees Celsius

An uptick in wind speeds led to a sudden bettering of Delhi’s pollution levels on Saturday as the city’s air quality improved to the “moderate” zone.

Bougainvillea flowers in full bloom near JLN Stadium in New Delhi on Saturday. (Sanchit Khanna/HT Photo)

After seven straight days of “moderate” air, Delhi’s pollution levels had deteriorated to the “poor” zone on Friday due to a drop in wind speed, as the city recorded an average air quality index (AQI) reading of 202, according to the Central Pollution Control Board’s daily national bulletin. However, the winds picked up again on Saturday, as the AQI improved to 158 (moderate).

“The wind speed was around 10-15 kmph on Saturday, with occasional gusts of 20 kmph, which is enough for dispersal of pollutants,” Mahesh Palawat, vice president at Skymet, said.

Meanwhile, Delhi’s minimum saw a sharp rise on Saturday, as the city logged the day’s low at 13.4 degrees Celsius (°C) — an increase of 3.2° from Friday’s minimum. This was, however, 0.6°C below the normal for this time of the year.

The maximum, too, saw a slight increase and was 31.1°C — 2.7°C above the normal. The maximum was 29.5°C a day before.

The India Meteorological department (IMD) has forecast a fresh western disturbance to influence the western Himalayan region from Sunday, which is likely to cause cloudy skies in the National Capital Region (NCR) in the coming week, with parts of Delhi predicted to record light rain.

Palawat said the effects of the western disturbance are likely to continue till March 15-16.

Separately, the Air Quality Early Warning System (AQEWS) for Delhi predicted that the air quality is expected to be in the moderate category on Sunday, and then deteriorate to poor in the next few days.

“The air quality is likely to be in the moderate category on Sunday. The air quality is likely to be in the poor category from Monday to Tuesday. The outlook for the subsequent six days is that the air quality is likely to be in the poor to moderate category,” the AQEWS bulletin said on Saturday evening.