Marine ecosystems along the North Coast of California exist in a highly energetic and variable oceanographic environment that strongly influences the dynamics and structure of the diverse marine populations that call this region home (Barth and Checkley 2009). Understanding the effect of marine protected areas (MPAs) implemented in this region therefore requires information on how oceanographic conditions vary over space and time. Baseline observations collected before or soon after implementation of MPAs depend in part on the oceanographic history of the region, and ongoing ocean observations can inform analysis of ecological and economic responses to MPAs over time (White et al. 2010). This report synthesizes a diverse suite of observations to provide this essential oceanographic context for baseline ecosystem studies (BES) in the North Coast Study Region (NCSR) and to establish a foundation for integrative studies, ongoing monitoring, and adaptive management of marine resources in the region. The primary intent of this work is to inform analysis of data collected during the BES and to the extent possible, to inform the design of future monitoring programs. Our foremost purpose is to provide historical perspective on conditions occurring during the 2014‐2016 Baseline Study Period (BSP). A great deal of this effort has been directed towards developing information specific to the NCSR that captures region‐specific responses to the unprecedented, persistent 2014‐2016 North Pacific marine heatwave (NPMHW) (Di Lorenzo and Mantua 2016) and associated ecosystem responses (including an equally unprecedented, massive, and persistent harmful algal bloom during 2015) (Leising et al. 2015, McClatchie et al. 2016).