Spatial patterns of trends in seasonal extreme temperatures in India during 1980-2010

Station level daily maximum and minimum temperature data spread across India were analyzed for trends in seasonal extreme temperature indices. The trends were calculated for the recent period of 1980-2010, when some of the warmest temperatures were recorded at the global scale. The results of the analysis revealed substantial variations in the spatial patterns of the trends. The majority of the study area experienced declining trends in diurnal temperature range during all seasons. However, substantial variations were observed for the different extreme temperature indices. During the first half of the year, which constitutes the drier summer and winter months, a declining trend in extreme maximum and minimum temperature indices were observed over most of peninsular India and the reverse in northern India. The spatial patterns were in general similar for the first half of the year, winter and summer, which constitute the drier months. The spatial patterns can be attributed to both local and regional level processes, such as aerosol levels and land use land cover changes.