Light rain cools Delhi, but fails to reduce pollution

After a day of breathing relatively cleaner air on Wednesday, the IMD had forecasted that the air quality index (AQI) would improve because of possibilities of rain and strong winds. However, scanty showers and light winds spoiled the chances of AQI getting better.

Scanty rainfall and low wind speed prevented the air quality in Delhi from improving on Thursday, scientists at the India Meteorological Department (IMD) said. The air quality on Thursday was recorded in the ‘very poor’ category, deteriorating from being ‘poor’ on Wednesday.

A man walks amid smog after sudden rain in New Delhi. (Biplov Bhuyan/HT photo)

After a day of breathing relatively cleaner air on Wednesday, the IMD had forecasted that the air quality index (AQI) would improve because of possibilities of rain and strong winds. However, scanty showers and light winds spoiled the chances of AQI getting better.

Central Pollution Control Board (CPCB) data shows that on Thursday the overall AQI in Delhi was recorded at 309, as against 214 on Wednesday. IMD scientists said on Friday too, the AQI is expected to remain in the very poor range. However, the situation is likely to improve on Saturday and Sunday.

“If the rainfall would have been heavier, the effect on the AQI would have been significant. But the scanty rain acted as a binding agent for pollutants, instead of washing them away. The winds ranged between 14kmph and 15kmph, which was also not strong enough,” said Kuldeep Srivastava, head of IMD’s regional weather forecasting centre.

He said on Friday, there is a forecast of fog in the morning when the air quality will deteriorate but by 10am after the sun completely shines pollutants will disperse.

On Thursday, the maximum temperature in Delhi was 23.4 degree Celsius, nearly six notches below normal. The minimum temperature settled at 18.2 degree Celsius, four degree above normal.

The city recorded 0.8 metres of rainfall and the relative humidity was around 85%.

There are chances of the wind picking up speed on Saturday and Sunday to around 20kmph, which will marginally improve the city’s air quality, scientists said.