The southwest monsoon is expected to arrive over the Andaman Sea and nearby parts of the Andaman and Nicobar Islands later this week, earlier than the normal schedule, according to the India Meteorological Department (IMD).
In its daily weather bulletin issued on Tuesday, the IMD said that conditions are becoming favourable for the onset of the southwest monsoon over parts of the south Bay of Bengal, Andaman Sea, and the Andaman and Nicobar Islands by the end of this week.
If the forecast comes true, the monsoon would reach the south Andaman Sea nearly five to six days ahead of its usual onset date. Normally, the monsoon enters this region around May 22. Last year, in 2025, the monsoon arrived in the Andaman Sea region on May 13.
The arrival of the monsoon over Kerala around June 1 officially marks the beginning of India’s four month rainy season. However, weather experts have clarified that an early onset over the Andaman Sea does not necessarily indicate better rainfall or faster progress of the monsoon across the country.
The southwest monsoon remains crucial for India as more than 70 per cent of the country’s annual rainfall is received during the June to September season. The rainfall supports agriculture, replenishes groundwater reserves and reservoirs, and plays a major role in electricity generation and the overall economy. India’s average seasonal rainfall is around 880 mm.
The IMD also noted that a low pressure area has developed over the southwest Bay of Bengal. According to the department, the system is expected to intensify over the next 48 hours and is currently associated with a cyclonic circulation over the region, helping create favourable conditions for monsoon advancement.
Despite the possibility of an early onset, the IMD’s first stage Long Range Forecast released in April had predicted below-average rainfall for the 2026 monsoon season. The forecast estimated rainfall at 92 per cent of the long-period average calculated between 1971 and 2020.
The progress of the southwest monsoon is closely watched every year because of its direct impact on farming, water availability, food production and economic activity across the country.