Shillong, Sep 18: The Northeast is getting hit from both ends — heavier one-day downpours and longer dry spells — a 52-year climate analysis has found.
The study, covering 1971 to 2022 across Assam, Meghalaya, Nagaland, Manipur, Mizoram, Tripura, Arunachal Pradesh and Sikkim, was published in the International Journal of Climatology on Friday.
Titled “Evolution of Climate Extremes Over the Indian Subcontinent Using a Revised CEI”, it was carried out by researchers at the India Meteorological Department (IMD), Atria University, Bengaluru, and the National Centre for Medium Range Weather Forecasting (NCMRWF).
It combined seven hazards — including daytime heat, humid heat, heatwave severity and drought — into a single India Climate Extremes Index using IMD data and Mann-Kendall trend testing.
The findings said that the Northeast is the only region in India with a clear, statistically significant rise in extreme one-day rainfall, which the authors link to a warming Bay of Bengal, more moisture in the air and the region’s complex terrain. At the same time, dry spells are increasing.
This dual trend points to a more unstable monsoon, not simply wetter or drier weather, the authors said.
“The northeast is the one region swinging between extremes, heavier single-day downpours on one side and longer dry spells on the other. That combination points to a more unstable monsoon, and it calls for both flood preparedness and drought planning,” co-author Dr M Rajeevan, former Secretary, Ministry of Earth Sciences said.
Lead author Thota Mohan, NCMRWF, added, “The northeast is the only part of the country where we see a clear rise in short, intense one-day rainfall, even as dry spells lengthen. It stands apart from the heat-and-drought story that dominates the rest of India.”
The study calls for flood preparedness and rainfall-variability management to be the priority for the Northeast, along with cross-sector action in agriculture, water, health and infrastructure, and sharper local monitoring to catch extremes that regional averages hide.
