The India Meteorological Department (IMD) has announced that the southwest monsoon has arrived early over parts of the South Bay of Bengal, South Andaman Sea, Nicobar Islands, and sections of the North Andaman Sea as of May 13, 2025. This is the earliest onset in these regions in the last seven years, arriving ahead of the usual May 19 date for the South Andaman Sea.
The IMD attributes this early arrival to several atmospheric and oceanic factors. These include higher-than-normal minimum temperatures in North India, strengthening westerly winds at lower atmospheric levels, and easterly winds at upper levels. Additionally, pre-monsoon rainfall and thunderstorms over the southern peninsula for about 40 days, along with elevated pressure over the northwest Pacific Ocean, have contributed to the advancement.
Looking forward, the conditions appear favorable for the monsoon to advance into the South Arabian Sea, Maldives, Comorin region, and more parts of the South Bay of Bengal and Andaman Sea over the next few days. The IMD forecasts above-normal rainfall for the monsoon season, estimating it at 105% of the Long Period Average of 880 mm.
This early onset is expected to benefit agricultural activities, especially in regions like Kerala and Andhra Pradesh, where the monsoon is crucial for sowing kharif crops. The IMD forecasts that the monsoon will reach Kerala by May 27, which is earlier than the typical start date of June 1.
However, the early monsoon also presents challenges. The sea surface temperatures in the Bay of Bengal have risen to 31-32°C, creating favorable conditions for the formation of tropical systems. A cyclone is likely to develop in the south Bay of Bengal within the next few days, potentially affecting regional weather patterns.
