The year 2025 concluded with the southern peninsular region of India receiving rainfall very close to its historical average during the crucial northeast monsoon season, as per the final assessment by the India Meteorological Department (IMD). The region recorded a cumulative rainfall of 283.4 mm from October to December, which represents a minor departure of just 3.7 per cent below the long-period average, classifying it as 'near normal'.
A Season of Contrasts: October Surplus vs. November-December Deficit
The overall near-normal figure masks significant monthly variations within the three-month season. The season commenced on a remarkably wet note in late October, primarily supercharged by Cyclone Montha. This weather system made landfall near Kakinada along the Andhra Pradesh coast, dumping heavy rains and leading to October's rainfall being 40 per cent above normal.
However, the following months saw a dramatic reversal in trend. November recorded a significant rainfall deficiency of 43 per cent, and December (till the 30th) was 35.9 per cent below average. IMD officials attributed this sharp decline to fewer-than-usual rainfall-bearing weather systems developing over the Bay of Bengal during these two months.
State-Wise Performance and Core Monsoon Zone
The northeast monsoon, also termed the winter monsoon, is vital for several southern regions. Its core rainfall-receiving areas include coastal Andhra Pradesh, Rayalaseema, Tamil Nadu, Puducherry, Karaikal, Yanam, south interior Karnataka, Kerala, and Mahe. For Tamil Nadu, this season is particularly critical as it supplies more than half of the state's annual rainfall.
Despite the late-season dry spell, most sub-divisions reported normal seasonal rainfall. The notable exception was Kerala, which ended the season with a 21 per cent deficiency, marking the lowest rainfall among the southern states. The timely and vigorous onset in October helped balance the deficits later, ensuring the seasonal tally stayed close to normal for others.
Completing a Year of Adequate Rainfall
This near-normal northeast monsoon performance in 2025 ensured that India experienced good and widespread rainfall during both monsoon seasons of the year—the southwest monsoon (June-September) and the northeast monsoon. The season officially concludes on December 31, though the complete withdrawal of monsoon conditions often extends slightly beyond this date.
The IMD's data underscores the inherent variability of the northeast monsoon, where a single major event like a cyclone can significantly influence the final outcome. The resilience of the seasonal total despite substantial deficits in two months highlights the importance of intense short-period rainfall events in the overall hydrological balance of southern India.
