2. Trend of Climatic Components in Sub-Himalayan West Bengal: Evidence from Jalpaiguri District During the Last Century (1901–2000)

The monsoonal rainfall in North-East India, including the study region (Jalpaiguri district, located in the eastern Himalayan foothills), is decreasing, and heavy precipitation event days have been increasing. In this study, different climatic components, such as average monthly minimum temperature, maximum temperature, precipitation, and wet days’ frequency of Jalpaiguri district over a century (1901–2000), have been investigated in order to figure out the changing pattern of climate. For robust interpretation, the Mann-Kendall trend and Sen’s slope statistical methods were applied for trend analysis of each climatic component. At the same time, a hundred-year temperature anomalies (average, minimum, maximum) have also been calculated. The linear trend of the annual average temperature anomaly in Jalpaiguri has indicated that the temperature anomaly was increased by about 0.006 °C/year. It was highest in 1999 (+1.2 °C); simultaneously, the temperature has risen significantly by 0.01 °C in February and November in the last century. The Mann-Kendall test reveals a significant drop in the annual rainfall by 0.93 mm in June, followed by 0.18 mm in August during the last century (1901–2000). In 1955, July received a record-breaking rainfall (1105.93 mm), the highest monthly rainfall in the last century.