The large disturbance that became Agnes was first detected over the Yucatan Peninsula of Mexico on June 14. The system drifted eastward and became a tropical depression later that day and a tropical storm over the northwestern Caribbean on the 16th.
Agnes turned northward on June 17 and became a hurricane over the southeastern Gulf of Mexico the next day.
A continued northward motion brought Agnes to the Florida Panhandle coast on June 19 as a Category 1 hurricane.
Agnes turned northeastward after landfall and weakened to a depression over Georgia. However, it regained tropical storm strength over eastern North Carolina on June 21 and moved into the Atlantic later that day. A northwestward turn followed, and a just-under-hurricane-strength Agnes made a final landfall on the 22nd near New York, New York. The storm merged with a non-tropical low on June 23rd, with the combined system affecting the northeastern United States until the 25th.
Agnes was barely a hurricane at landfall in Florida, and the effects of winds and storm surges were relatively minor. The major impact was over the northeastern United States, where Agnes combined with the non-tropical low to produce widespread rains of 6 to 12 inches with local amounts of 14 to 19 inches. These rains produced widespread severe flooding from Virginia northward to New York, with other flooding occurring over the western portions of the Carolinas.
Agnes caused 122 deaths in the United States. Nine of these were in Florida (mainly from severe thunderstorms) while the remainder were associated with the flooding. The storm was responsible for $2.1 billion in damage in the United States, the vast majority of which came from the flooding. Agnes also affected western Cuba, where seven additional deaths occurred.
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