Tamil Nadu is likely to receive rainfall largely within normal limits during the South-West monsoon season this year, according to a district-level seasonal forecast released by the Tamil Nadu Agricultural University (TNAU).
The June-September rainfall forecast for the 38 districts in the State was developed using the Southern Oscillation Index and Sea Surface Temperature values of the Pacific and Indian Oceans, based on Australian Rainman International V.4.3 software at Agro Climate Research Centre of TNAU, Coimbatore. The probability level is 60 per cent, said a press release from the university.
TNAU said most districts are expected to receive normal rainfall, defined as within ±10 per cent deviation from the long-term average. However, near-normal rainfall with a deficit exceeding 10 per cent is forecast for Coimbatore, Erode, Tiruppur, Dindigul and Theni districts.
Chennai, Chengalpattu likely to see near-normal rainfall
Among major districts, Chennai is expected to receive 430 mm of rainfall, against the normal 440 mm, while Chengalpattu may receive 438 mm, against the usual 450 mm. Cuddalore and Vellore are forecast to receive rainfall on par with their long-term averages.
In the western region, Coimbatore is projected to receive 178 mm of rainfall, against the normal 210 mm, while Tiruppur may receive 129 mm, compared with its average of 151 mm. Erode is likely to record 231 mm, down from the normal 260 mm.
Tirunelveli may record sharpest rainfall deficit
Tirunelveli is expected to witness the sharpest deficit, with rainfall projected at 108 mm, down from the normal 128 mm, marking a 16 per cent decline. Kanyakumari, categorised as a high rainfall zone, is likely to receive 478 mm, against its normal of 491 mm.
The university said the forecast will help farmers and policymakers make informed decisions on crop planning, irrigation scheduling, and water resource management ahead of the monsoon season.
Published on May 16, 2026