Repeat trans-Pacific hydrographic observations along the pathway of Lower Circumpolar Deep Water (LCDW) reveal that bottom water has warmed by about 0.005 to 0.01¿C in recent decades. The warming is probably not from direct heating of LCDW, but is manifest as a decrease of the coldest component of LCDW evident at each hydrographic section. This result is consistent with numerical model results of warming associated with decreased bottom water formation rates around Antarctica.