We use a pair of decadally resolved planktonic foraminiferal δ18O records from Santa Barbara Basin (SBB) to show that the warmest interval of the current interglacial, the middle Holocene, was characterized by increased decadal- to centennial-scale climatic variability. Modern relationships between the Pacific Decadal Oscillation (PDO), the El Ni¿o-Southern Oscillation (ENSO), and upper water conditions in SBB also suggest a preference of the northeast (NE) Pacific climate during the warm mid-Holocene toward the warm phase of the PDO and more intense ENSO warm events (El Ni¿os). In the context of future climate, this study suggests increasing decadal- to centennial-scale climatic variability in a globally warmed world.