Wintertime climatic trends in the western Himalayas A. P. Dimri & S. K. Dash Received: 11 May 2009 /Accepted: 27 July 2011 / Published online: 18 August 2011 # Springer Science+Business Media B.V. 2011 Abstract Northern Indian rivers are primarily fed by wintertime (December, January, February—DJF) precipitation, in the form of snow—yielded by eastward moving synoptic weather systems called Western Disturbances (WDs), over the western Himalayas (WH). This accumulated snow melts during ablation period. In the context of today’ s warming atmosphere, it is imperative to study the changes in the temperature and precipitation patterns over the WH to assess the impact of global warming on climatic conditions of the region. Keeping that in mind, observational analysis of temperature and precipitation fields is planned. In the present study various climatic indices are analyzed based on wintertime (DJF) data of 30 years (1975–2006) obtained from the Snow and Avalanche Study Establishment (SASE), India. Results indicate enhancement in the surface air temperature across the WH. Percent number of warm (cold) days have increased (decreased) during 1975–2006 over the WH. Further analysis of precipitation reveals slightly decreasing but inconsistent trends. 1 Introduction During the past few years, numerous researchers have examined the local trends in temperature and precipitation over various regions of the world. Zhang et al. (2000) have inferred that the annual mean temperature in the southern part of the Canada has increased by about 0.9°C and there has been approximately 12% increase in the annual precipitation. Klein-Tank and Konnen (2003) have found the occurrences of fewer cold nights, more warm days and an increase in the number of extreme wet days over Europe during 1946–99, although the spatial coherence of the trends was low in case of precipitation. Similar results were reported by Easterling et al. (2003) in Africa over a period of 1961–90. Qian and Lin (2004) found that in China, the number of cold nights Climatic Change (2012) 111:775–800 DOI 10.1007/s10584-011-0201-y A. P. Dimri (*) School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India 110067 e-mail: apdimri@hotmail.com S. K. Dash Centre for Atmospheric Sciences, Indian Institute of Technology, Hauz Khas, NewDelhi 110016, India