This dataset contains monthly kelp canopy extent maps for the California coastline. Products are provided as shapefiles and were originally generated from 3 m Planet Dove GeoTIFF classifications. For each month, at least five cloud-free Planet Dove images were acquired and classified using a VGG16-U-Net model trained to identify four classes: kelp, seawater, land, and waves. Monthly kelp canopy extent was produced with a majority filter: pixels labeled as kelp in at least 50% of the input images were retained in the final composite. For full methodological details, see Cavanaugh et al., “High-resolution Planet Dove data identify local drivers of kelp canopy persistence.” Users should cite this publication when using these data. Contents and file structure One ZIP file per year-month (e.g., YYYY_MM_PlanetDove_KelpPolygon.zip) Each ZIP contains two shapefiles (with their associated .shx, .dbf, .prj, etc.): YYYY_MM_California_KelpCanopy_KelpPresence.shp (polygons indicating mapped kelp canopy for that month). YYYY_MM_California_KelpCanopy_AreaSurveyed.shp (polygons delineating the area that was surveyed by the model (i.e., locations that were covered by at least 1 Planet Dove image and that were not masked for land or clouds). Areas with no data are excluded from this layer. Spatial & temporal extent Spatial extent: California coastline Temporal extent: September for years 2017-2024