Parts of Northeast India Exit Tropical Climate Zone After Seven Decades, Study Finds

A climate assessment released by the Indian Meteorological Department indicates that parts of the Gangetic plain in West Bengal and several districts across the northeastern states have moved out of the tropical climate classification over the last seven decades. The study compared temperature and precipitation records from the 1950s with recent data, finding a consistent rise in mean annual temperatures and a shift in seasonal rainfall patterns.

The analysis attributes the transition to a combination of global warming and regional land‑use changes, which have altered the thermal regime of the area. As temperatures cross the threshold that defines the tropical zone, the regions are now classified as subtropical, according to the Köppen climate system.

Researchers warn that the re‑classification could affect agriculture, biodiversity and water resources, as crops and ecosystems adapted to tropical conditions may face stress. The department plans to monitor the trend closely and advise state governments on adaptive measures.

The findings underscore the broader impact of climate change on India's diverse climatic zones, highlighting the need for targeted mitigation and resilience strategies in vulnerable regions.