IIT Madras and Guwahati University develop new method to identify monsoon arrival

Researchers from IIT Madras and Assam's Guwahati University have developed a new method that can accurately identify when the monsoon has arrived at a specific location. According to an NDTV report, researchers have prepared a 'climate-network' approach, which can clarify the difference between short-term local rainfall periods and the large-scale, continuous monsoon system. This research will make it possible to know when the monsoon may arrive at a specific location.

A press release shared by IIT Madras with NDTV states that, by monitoring how clusters of local rainfall arrival across India transform into a vast and interconnected system, the study presents an unbiased method to identify large-scale monsoon arrival at individual locations. This approach can complement traditional monsoon arrival definitions and provide more reliable information for decisions related to sowing, water resources, food security, and flood preparations.

According to official documents, this study treats geographical locations as 'nodes' in a climate network. As explained in this understanding, links between nodes represent spatial connections between locations experiencing local rainfall arrival. Researchers monitored the development and movement of these local arrival clusters.

According to Professor R.I. Sujith, head of 'Critical Transitions in Complex Systems' (CoE-CTCS) at IIT Madras, by avoiding false arrivals, our new perspective of defining large-scale monsoon arrival at every location will give farmers time for sowing and help policymakers in planning for food security and water resource management. Professor B.N. Goswami of the ST Radar Centre at Guwahati University added that the aim of this method is not to replace traditional operational definitions, but to complement them. According to him, the unique feature of this method is that it links local observations with large-scale monsoon organization, allowing for the identification of large-scale arrival at various locations through a single framework.

Researchers noted that, for example, small rainfall clusters, including thunderstorm activity, develop in North-East India during April. As the season progresses, the North-East India clusters develop and merge with other clusters connected to the Bay of Bengal region. Researchers identified the sudden development of this resulting cluster as a large-scale monsoon arrival in North-East India.

According to the study, the same process occurs sequentially over the Indian peninsula. A small cluster develops over Kerala due to local rainfall activity. When this cluster moves west from North-East India and connects with the largest rainfall arrival cluster, researchers identified this transition as a large-scale monsoon arrival on the Indian peninsula. This method enables the distinction between an isolated local rainfall period over Kerala and the establishment of the large-scale monsoon system.

Using their new definition, researchers observed the 2026 monsoon and found that the large-scale monsoon arrival on the Indian peninsula occurred on June 22, 2026.

Among Indian institutions, IIT Madras is a leading technological institution known for research in the fields of engineering and science. Guwahati University is one of the premier academic institutions in Assam.