Extreme Temperature and Rainfall Event Trends in the Middle Gangetic Plains From 1980 to 2018

Regional-level studies aimed at identifying and assessing various types of extreme weather events and comprehending their effects on various sectors are crucial. In the present study, we have utilized the RClimDex software to compute the trend in temperature and precipitation extreme events in the Varanasi district of Uttar Pradesh, India, from 1980 to 2018. We employed both Mann–Kendall test and linear regression to test the statistical significance of the computed trend. Out of 13 temperature indices, 8 showed a significant trend while the remaining showed a non-significant trend. The annual mean maximum temperature, warm days, diurnal temperature range and a monthly minimum of maximum temperature had decreased significantly by 0.029ºC, 0.159 days, 0.032ºC and 0.122ºC/yr respectively, whereas cool days and cold spell duration had increased significantly by 0.264ºC and 0.372 days/yr respectively, indicating an increased cooling effect over the study area. Similarly, out of the 11 rainfall indices, only two showed a significant trend, while the remaining showed a non-significant trend. The increasing drought over the study area is evident as the number of rainy days and consecutive wet days have decreased significantly by 0.262 days and 0.058 days/yr respectively, with a non-significant increase in consecutive dry days during the same period. The weak negative non-significant trend of a maximum of five consecutive days of rainfall, very heavy rainfall days and total annual precipitation indicate the decreasing trend of floods. This study stresses the development of adaptation plans to overcome the adverse consequences of extreme weather events in Varanasi district.