Trans Gangetic Plains of India: Understanding Maximum Temperatures Trends across Seasons and Methods

Climate change and maximum temperature rise affect various aspects of human life, including agricultural production. The paper evaluates the variability in maximum temperatures across 47 districts of the Trans-Gangetic Plains, a pivotal Agro-Climatic Zone in India, over 1901- 2021. It investigates annual as well as seasonal, i.e., summer, monsoon, post-monsoon, and winter seasons maximum temperatures by employing four distinct methods: Mann Kendall (MK) Test, Modified Mann Kendall (MMK) Test, Innovative Trend Analysis (ITA), and the Simple Linear Regression (SLR) Model. We found a significant rise in annual maximum temperatures across Trans-Gangetic Plains, ranging from 0.002°C to 0.053°C per decade over 1901-2021. The last three decades (1991-2021) have had more pronounced maximum temperature trends than previous decades. Further, three seasons, i.e., summer, post-monsoon, and winter, demonstrate rising maximum temperatures with the highest rise witnessed in winter season (0.044°C to 0.099°C per decade). However, monsoon season show declining maximum temperature trends across all 47 districts, ranging between –0.016°C to –0.067°C per decade. Further, ITA captures more significant trends than MK, MMK, and SLR. The results advance the understanding on maximum temperatures’ variability using different methods, identify distinct patterns for 47 districts of Trans-Gangetic Plains, and thus demand a comprehensive Agro-Climatic Zone specific response plan, including adaptation and mitigation strategies, to address these changes.