Delhi weather update: AQI still 'poor'; artificial rain planned post-Diwali

The IMD has forecast hazy mornings through the week, with smog or shallow fog likely from October 19 onwards. The Delhi government has also decided to conduct artificial rain after Diwali

Delhi weather update: According to the IMD forecast, smog or shallow fog is likely to develop in several areas from October 19, with mist or haze expected during the early hours of the day, throughout the week. While skies will remain mostly clear, partially overcast conditions with mild north-easterly winds are anticipated by October 21.

 

Meanwhile, on Wednesday, Delhi Environment Minister Manjinder Singh Sirsa announced that the city’s first-ever attempt at artificial rain through cloud seeding will be carried out after Diwali, subject to approval from the India Meteorological Department (IMD).

Delhi Weather Update in Oct 2025

Over the next seven days, Delhi's minimum temperature is predicted to be between 16°C and 21°C, signalling progressively colder mornings as winter draws near. It is anticipated that the highest temperature would stay constant between 31°C and 34°C.

 

What is Cloud Seeding, and how will it be implemented in the National Capital?

As a weather modification technique, cloud seeding entails introducing materials like silver iodide (AgI) into clouds to increase their capacity to generate rainfall. The Indian Institute of Technology (IIT) Kanpur, which has specially adapted its Cessna-206H aircraft for this project, is working with the Delhi project to carry it out.

 

Nimbostratus clouds, which normally form between 500 and 6,000 meters above ground level, are perfect for seeding, but they need to have at least 50 per cent moisture, according to experts at IIT Kanpur. 

 

Currently, there is not enough moisture or cloud density in Delhi's skies for seeding to be successful. An IIT official working on the project stated, "We are closely monitoring atmospheric conditions, waiting for the right window.” Five trials are scheduled to take place around northwest Delhi, according to officials. 

 

In order to determine whether artificial rain is feasible in various scenarios, each test will be carried out at different humidity levels: 50%, 70%, and less than 50%. A senior environment department official stated, "We’ll also analyse water samples after each trial to ensure there’s no harmful environmental impact." 

How will artificial rain help in reducing Delhi pollution?

Although the exact amount is unknown, it is generally believed that rain will significantly improve Delhi's air quality, perhaps by as much as 50 to 80 points on the Air Quality Index (AQI).

 

Dipankar Saha, former head of CPCB’s air laboratory, stated, “If the AQI is ‘very poor’, it may improve to ‘poor’, and if it is ‘poor’, it may improve to ‘moderate’. You are not likely to see a significant improvement". He said that many other factors, such as wind speed, the region of influence, and the severity of the rain, will affect the situation. Saha further added, “If it is a drizzle to light rain, it will not make much difference. One needs good intensity and strong winds to have a washout effect".

About the ‘Artificial rain at Delhi’ project

The Directorate General of Civil Aviation (DGCA) had granted clearance a day earlier, and on September 25, the Delhi government signed a Memorandum of Understanding (MoU) with IIT Kanpur to carry out the testing. 

 

Subject to strict requirements, including no flights over restricted or prohibited zones, no aerial photography or survey, no foreign crew involvement, and prior Air Traffic Control clearance, the DGCA's letter, dated September 23 and viewed by HT, permitted the use of IIT Kanpur's aircraft between October 1 and November 30.

 

The project has also received approval from over 10 other government agencies, including the Uttar Pradesh government, the Airports Authority of India, the Bureau of Civil Aviation Security (BCAS), and the Union ministries of environment, defence, and home affairs.  

 

The ₹3.21-crore plan was approved by the Delhi Cabinet on May 7. The start of the southwest monsoon caused the experiments to be postponed from their original dates of late May and early June. Since the monsoon persisted until its formal withdrawal on September 24, a revised window in August-September was also missed.