Dust storm pushes Delhi AQI into ‘poor’; GRAP not invoked due to rain forecast

New Delhi: A dust storm early Friday morning led to a sudden spike in pollution levels across the city, pushing the air quality index (AQI) into the poor category even as the maximum temperature dropped by more than three degrees.

India Meteorological Department (IMD) issued a yellow alert for rain, thunderstorms and gusty winds on Saturday.

On a scale of 0 to 500, Delhi’s AQI stood at 266 (poor) at 4 pm on Friday, deteriorating sharply from 194 (moderate) a day earlier. The Commission for Air Quality Management (CAQM) said the deterioration was triggered by the dust storm in the early hours of the day. However, CAQM said it did not invoke the Graded Response Action Plan (GRAP), citing forecasts of improving air quality due to expected rainfall.

“Today, Delhi’s average air quality index crossed 200 and reached 266 (poor category) at 4 pm, mainly due to a dust storm earlier in the morning. Forecasts from IMD and IITM suggest light rain is likely on April 3-4, along with improving weather conditions in the following days. Since the overall AQI is expected to stay in the moderate range, the sub-committee on GRAP said the invocation of Stage I is not required at the moment,” said CAQM.

The maximum temperature on Friday was recorded at 33.7 degrees Celsius, close to the seasonal normal, against 36.8 degrees Celsius a day earlier. The minimum temperature rose sharply due to overnight cloud cover, with Safdarjung recording 22.4 degrees Celsius — four degrees above normal — compared with 18.9 degrees Celsius the previous day.

According to IMD, a fresh western disturbance is likely to affect northwest India from April 7. Rain is expected on Saturday, for which a yellow alert has been issued, and there is also a possibility of showers on April 5, followed by a brief break on April 6. Rain is again likely on April 7 and 8.

“Maximum temperatures are expected to fall by 3-5 degrees Celsius over the next three days, rise by 1-2 degrees Celsius over the subsequent two days, and then dip again by 2-4 degrees Celsius. Temperatures are likely to remain below normal to appreciably below normal over the next seven days,” IMD said.

The maximum temperature on Saturday is expected to hover between 29 and 31 degrees Celsius.