Increase in Spatial Spread of Extreme Warm Day Temperature Events: Regional to National Perspective for India (1951–2014)

This study analysed gridded temperature dataset for last six decades over India and its different agroclimatic zones to determine the changes in land area affected by extreme warm day temperatures. The results indicated an unequivocal increase in the area influenced by different levels of extreme warm days over the country; the rate was significantly higher during the last three decades. The increase in land area affected by extreme-of-extreme temperature events occurred at a higher rate compared to the lowfrequency extremes. Statistical tests indicated clear change in the probability distribution of the land area affected by extremes, signifying that comparatively high-frequency extremes are occurring over larger areas. The results showed regional dissimilarity, with five agro-climatic zones (ACZ-02, 09, 10, 11, 12) showing increase in land area under most levels of extremes, and three agro-climate zones (ACZ-08, 13, 14) showing increase in land area for a few extreme levels.