Daily sea‐water temperature measurements made at tide stations by the U. S. Coast and Geodetic Survey reveal anomalously low water temperatures during most summers at stations along the northern half of the east coast of Florida. The periods of colder water are accompanied by a lowering of sea level and by winds from directions most conducive to producing upwelling. Examination of daily variations in these factors at Daytona Beach during a year when the summer drop in mean water temperature exceeded 10°F shows the dependence of upwelling on the prevailing winds and suggests that the upwelling mechanism has no momentum but ceases at the coast as soon as the driving force is terminat