These data are the geochemical (from X-ray fluorescence spectrometry), grain size, lithological (loss on ignition), diatom assemblages (taxa counts), bathymetric, and radioactive isotopes (210-Pb, 137Cs) from sediments from Wildcat Lake, Point Reyes National Seashore, California, USA starting in 2021. Taken together, they provide evidence for extreme precipitation events linked to atmospheric rivers. They also indicate anthropogenic impacts in the watershed.