2 min readBengaluruMay 12, 2026 06:57 PM IST
The southwest monsoon is set to arrive over the Andaman Sea and neighbouring islands of Andaman and Nicobar islands later this week.
“Conditions are becoming favourable for onset of southwest monsoon likely over parts of south Bay of Bengal, Andaman Sea and Andaman and Nicobar Islands towards the end of this week,” India Meteorological Department (IMD) said in its daily weather forecast issued on Tuesday.
If realised, it would be an onset over the south Andaman Sea by five to six days in advance. In 2025, the monsoon hit the Andaman Sea region on May 13.
Climatologically, the normal date for the monsoon onset over this region is around May 22, followed by its advance further westwards towards mainland India. The normal date for the monsoon onset over Kerala is June 1, and that marks the actual commencement of the four-month season. However, early onset has no links to the monsoon progress or rainfall quantum.
The southwest monsoon is the primary rainy season over India, which receives over 70 per cent of its annual rainfall during the June – September period. The average seasonal rainfall of the country is about 880mm. The monsoon rainfall is vital for recharge of groundwater and reservoirs, agriculture, power generation and is directly linked to the country’s overall economic output.
On Monday, the Met department had informed of the development of a low pressure area in the southwest region of the Bay of Bengal.
The IMD further said, ” This system prevails over the same region. Over the next 48 hours, it will intensify. In association to this system, there persists a cyclonic circulation over the region.”
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This year, the IMD’s first stage Long Range Forecast released in mid-April had suggested below average seasonal rainfall over the country, which, quantitatively, was about 92 per cent of the long-period average (1971–2020).
