The mountainous region of the Upper Indus Basin is a critical source of water for Pakistan. Most flow in the upper Indus is derived from melting snow and glaciers and summer runoff is strongly correlated to winter precipi- tation and summer temperature, though links may operate in opposing directions in glacier-fed and snow-fed hydrological regimes. From 1961 to 1999 there were significant increases in winter, summer and annual precipita- tion and significant warming occurred in winter whilst summer showed a cooling trend. These trends will impact upon water resource availability. Relationships between climatic variability and large-scale climatic processes may be used to increase forecasting lag time for water resources.