Clearings in the marine-boundary-layer (MBL) cloud deck of the Pacific Ocean were studied. Remote sensing, reanalysis, and airborne data were used along with machine-learning modeling to characterize the spatiotemporal nature of clearings and factors governing their growth. The most significant implications of our results are linked to modeling of fog and MBL clouds, with implications for societal and environmental issues like climate, military operations, transportation, and coastal ecology.