Fog and low cloud cover (FLCC) have been shown to profoundly influence the climate experienced by ecosystems. However, how these controls play out across space, time and plant functional type is less well understood. In this study, we compare multiple datasets from coastal ecosystems in Central and Northern California. Our analysis compares both the weather conditions and ecosystem functioning under cloudy and clear sky conditions. In particular, we focus on the range of conditions experienced at the surface in coastal California, and the differences in responses related to plant types. Our work provides scientific evidence useful for land-use management decisions for species conservation and selection of crops and agricultural practices in the region.