The oceans are areas of high primary productivity which vary geographically. In general, coastal areas are more productive and host greater biodiversity than the open ocean. Coastal regions are usually limited to the continental shelf area and include areas of coastal upwelling. In these regions, ocean circulation is mainly influenced by topography and coastal winds. Coastal regions, being highly productive, concentrate a high percentage of the world's population and therefore have an essential socio-economic relevance. The Northwest coast of the Iberian Peninsula (NWIP) is one of the areas of the world with the highest primary productivity since several factors converge in this area:(1) it is located at the northern limit of the Canary Islands upwelling system,(2) a large number of large rivers flow into it, providing nutrients, and (3) it has a peculiar morphology with the presence of the Galician estuaries to the north. Over the years, numerous scientific investigations have been carried out in various fields to try to better understand the hydrodynamic behaviour of the NWIP coast. Despite this, many questions remain unanswered, and even more so if we take into account the current scenario of climate change, both natural and anthropogenic, that we are facing. The study of the effects of climate change on the NWIP coast is a difficult but necessary task, as it helps to understand its vulnerabilities and allows planning strategies for mitigation and adaptation. Numerical models are very useful tools for carrying out this task, since they allow us to simulate, for example, the water temperature in the future under various climate change scenarios. In addition, the models also allow us to simulate historical events in order to analyze them in detail. For all the above described, the main objective of this thesis is to contribute to the oceanographic knowledge of the NWIP coast and help to evaluate the impact that climate change may have on the region. For this purpose, the numerical model Delft3D was used, which allows improving the spatial resolution of global climate models that cover larger areas, in order to solve regional and even local processes in a more accurate way. The NWIP coast is a complex system in which the morphological characteristics of the coast, the bathymetry, the presence of freshwater from the discharge of the main rivers and the wind regime that controls the upwelling and downwelling cycles modifies the general circulation. The complexity of the system makes the application of numerical models, such as Delft3D, to this area an arduous task. First, it is necessary to generate a mesh whose resolution is adequate to reproduce the hydrodynamics of the area properly. Also, it must be taken into account that the simulations require a high computational cost, so it is necessary to reach a compromise between these factors. This thesis was carried out using two different meshes, a multi-domain one covering the NWIP from 10.20 to 8ºW and from 40 to 43.75 ºN, and a single-domain one covering from 10.00 ºW to 8.33 ºW and from 41.18 ºN to 43.50 ºN. The multi-domain mesh is composed of five interconnected domains whose horizontal resolution varies, with the coastal domains having a higher resolution than the ocean domain. This configuration was used to assess the effect of climate change on the upwelling system. The single-domain mesh was used to carry out specific studies in the area of the Rías Baixas and the Minho River estuary. Once the mesh is created, it is necessary to calibrate the model. During the calibration process, the model is run, the results are compared with field data or results from other validated simulations, the calibration …