The relationship between daily salmon catch and sea and weather conditions in Otsuchi Bay located at the center of the Sanriku Coast was analyzed in 1996 and 1997. The daily salmon catch reached a peak when the sea water temperature reached 13℃ level in both years. In 80% of cases, the salmon catch at the day after a rainfall (>5 mm) or strong westerly wind (>10 m/s) rose to over 1.5 times that of the previous day. The largest salmon catch of each year was observed to be on the day after the largest precipitation or the longest strong westerly wind. These data suggest that the homing behavior of chum salmon was affected significantly by sea water temperature, rainfall and westerly wind on the Sanriku Coast.