Northeast monsoon likely to set in around October 17 or 18: RMC

An upper air cyclonic circulation may emerge in Andaman Sea around October 11 and influence a low pressure area to form over the southeast Bay of Bengal around October 13. | Photo Credit: R. RAGU Northeast monsoon, which is eagerly awaited to bring relief from rainfall deficit and replenish rapidly depleting water resources, is likely to set in over Tamil Nadu around October 17 or 18.As the State prepares for the onset of the NE monsoon later next week, the Regional Meteorological Centre (RMC) has forecast a gradual dip in the temperatures from October 16.With the Southwest monsoon expected to retreat completely from the south peninsula by October 15, conditions could turn favourable for a reversal in wind patterns and arrival of NE monsoon in the following days.An upper air cyclonic circulation may emerge in Andaman Sea around October 11 and influence a low pressure area to form over the southeast Bay of Bengal around October 13.V.R. Durai, Head, Regional Weather Forecasting Centre, RMC, said the weather system was being monitored for its intensity and path. “If it moves towards land or the Tamil Nadu coast, it will help enhance conditions for a reversal of wind pattern to northeasterlies, potentially accelerating the onset of the monsoon,” he said. However, the weather models indicate that the system is unlikely to intensify beyond a low pressure area.The RMC expects temperatures to gradually fall across the State after October 16 as moisture incursion and cloud cover would begin to increase. With the State still undergoing monsoon transition phase, some parts of the State, particularly north interior Tamil Nadu, may continue to experience above normal temperatures till October 14.On Saturday, Erode and Madurai airport recorded the State’s highest maximum temperature of 37 degrees Celsius for the day. Many other weather stations also recorded day temperature of two degrees Celsius above average.However, a weather system over Gulf of Mannar and adjoining south Tamil Nadu would trigger wet spell over south and interior parts of the State. Rainfall of light to moderate intensity may continue over south Tamil Nadu till October 16. Despite the rainfall, temperatures could remain elevated in some areas in the absence of sustained cloud cover during the monsoon transition period, officials said. Published - October 10, 2026 07:19 pm IST