Biogeographic provinces are categories used for comparing and contrasting biogeochemical processes and biodiversity between ocean regions. Provinces provide a framework for reasonable extrapolation of point or transect data to broader areas. However, their use is limited due to the non-automatic, subjective nature of province classification. Furthermore, it is unknown how province boundaries respond to seasonal and climate forcing. These issues make province related hypotheses difficult to test with static provinces. To solve this problem, we use objective classification on global remote sensing data to automatically produce time and space resolved ocean provinces. Seasonal patterns in province geography reflect well-known ocean processes. Our predictions of province boundaries are verified by in-situ ship track data and province distributions in the equatorial Pacific correlate well with ENSO indexes. This objective classification system captures spatial and temporal province dynamics and provides objective categories for cross-province biogeochemical hypotheses to be rigorously tested.