Northwestern North America is strongly influenced by the climatic cycles associated with the ENSO (El Niño-Southern Oscillation). These cycles are often reflected in the inter-annual variations of air temperature and precipitation, which in return are expected to affect streamflow characteristics of rivers in this region.  However, the response of streamflow to ENSO events is not straight forward, being complicated by land characteristics.  Since most hydrometric stations in the region have short records, simulation is needed to investigate possible connections between climatic variations and streamflow. The discharge of selected hydrometric stations was modelled using the SLURP hydrological model with climatic inputs from a nearby station possessing at least 30 years of data.  Streamflow was analysed in conjunction with temperature and precipitation to examine how strong the streamflow characteristics are influenced by the ENSO effects. It was found that the location of each river basin is influenced by ENSO events to a different extent, and the strength of the ENSO effect on streamflow depends on the proximity of the basin to the area most affected by changes in the atmospheric circulation, basin size, topography and other land characteristics such as storage. Results of this study indicate that within a region that is generally affected by ENSO, the climatic effect may or may not be reflected in the streamflow record. On the other hand, through modelling, the connection between precipitation, temperature and streamflow can be extended to ungauged rivers, and streamflow changes can be projected for future climate scenarios.