Hydrographic data from profiling floats obtained during 2001–2004 were analyzed to study seasonal and interannual variability of temperature inversions (T-invs) in the subarctic North Pacific (SNP). In the western SNP and Bering Sea, the temperature minimum at the top of T-invs outcropped and was renewed every winter, causing a seasonal cycle in the magnitude of T-invs, with the maximum at the end of winter. In the Gulf of Alaska in the eastern SNP, the temperature minimum outcropped in winters 2002 and 2004, but scarcely outcropped in winter 2003. Consequently, the magnitude of the T-invs showed remarkable interannual variation; its monotonic decrease through winter 2003 overwhelmed the seasonal cycle. The year-to-year variation of the magnitude of the T-invs in each region of the SNP was consistent with and thereby attributable to that of the winter sea surface temperature anomaly there.