The statistical end to Northeast Monsoon 2025 is just a couple of hours away. Tamil Nadu and Pondicherry subdivisional rainfall will end at 428.9 mm. A negative anomaly of 3%, first time since 2018, NEM has not ended on a positive note. A season that promised so much with a blistering start during the early days of October ends with a whimper. December saw only 45.8 mm the lowest since 2018 which saw just 21.6 mm during the month. 2025 now becomes the 10th year since 2000 to see Northeast Monsoon on a negative note.
Though overall 2025 may have been a good year for most districts of TN & PDC the same cannot be said about NEM. For the year overall only 13 out of the 40 districts ended with negative anomaly. Chengalpattu saw the worst performance among all districts ending the year with 20% deficit while Dindigul, Karur and Tiruppur also saw nearly 20% deficit. But only 11 out of the 40 districts of TN & PDC ended on the positive side for NEM as a season. Chengalpattu once again the worst with a 35% deficit for the season.
As mentioned above statistically NEM will come to an end by 8:30 AM today. Rains after 8:30 AM today will get accounted to Winter rains for the year 2026. A trough of Easterlies continues to persist over South bay. With a weak cyclonic circulation also over the Equatorial waters there is a possibility for some rains as 2025 gives way to 2026.
Over the next couple of days parts of South TN may see moderate spells of rains. Few places in Thoothukudi, Virudhunagar, Ramanathapuram and Tirunelveli districts may see heavier spell of rains at times. Delta districts may also see moderate rains in a few places. These rains are unlikely to be too heavy to bring damage to standing paddy crops. Places in North coastal TN like Chennai may see light to moderate rains. Except for affecting the New Year festivities no major impact is likely.
Night time temperatures may remain slightly warmer than the past couple of weeks due to cloudy skies and rains. Models also indicate day time temperatures may be slightly warmer than normal during this period as well over parts of Peninsular India.