Long –Term Warming Trends in Ramanathapuram, Tamil nadu(1901–2023): A Statistical Climate Analysis

Abstract

This study investigates the long-term temperature trends in Ramanathapuram district, Tamil Nadu, India, over the period 1901–2023 using non-parametric statistical methods. The analysis includes Mann–Kendall trend tests, Sen’s slope estimation, and Pettitt’s change-point detection applied to monthly and seasonal minimum and maximum temperatures across four climatic periods. The results reveal a statistically significant increase in both temperature types during recent decades, especially from 1981 onward. Change points detected in the mid-1970s to early 1980s indicate a major climatic transition. The Sen’s slope estimator confirms a stronger warming trend in minimum temperatures than in maximum temperatures, with the most notable increases during the winter and northeast monsoon seasons. These findings highlight the impact of regional climate change in a semi-arid coastal district and suggest increasing vulnerability of local agriculture and water resources. The study provides valuable insights for climate adaptation and long-term planning in South Indian low-rainfall regions.