During the summer of 1955, record high sea water temperatures were observed in harbors and coastal waters of the North Atlantic States. Record air temperatures also occurred during this period. It is concluded that high sea water temperatures were due in large part to continued high air temperatures. The record low densities (or salinities) during the same summer corresponded with the periods of hurricanes Connie and Diane, hence the high runoff following these storms was doubtless responsible. The lag between rainfall and noticeable dilution and the delay in return to normalcy depend upon several factors· including the amount of rain, type of estuary, and size of drainage basin.