Changes in the climate regime can influence natural processes of a watershed ecosystem and have long-term implications on economic and ecological processes. A general consensus is that the average global surface temperature has risen by 0.45–0.6°C (0.8–1.0°F) and the average sea level has risen approximately 15–20 cm (6–8 in.) during the last century (IPCC 2001; USEPA 2004). While the climate change can occur naturally, population growth, fossil fuel burning, and deforestationhave acceleratedthe increaseof greenhouse gasses (carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons) in the atmosphere that trap heat and warm the earth system (USEPA 2004). This trend of increasing surface temperatures could impact the hydrologic cycle and various processes of a watershed system. Specific potential impacts include changes in runoff, nutrient enrichment, sediment loading, and evapotranspiration rates in a watershed system (Band et al. 1996; Chang et al. 2001; Evans et al.2003). In spite of extensive research on specific impacts of climate change, research and information on the impacts of climate change on watershed systems remain in its infancy. Evaluation of climate change on the watershed system is important to develop alternative strategies and policies to mitigate the impacts of global warming.