A polar front and an upper trough over the Yucatán Peninsula spawned a tropical depression on June 14. The storm emerged into the western Caribbean Sea on June 15, and by the following day, it strengthened into Tropical Storm Agnes. The storm curved northward and brushed western Cuba on June 17. Agnes continued to intensify, and on June 18, it was upgraded to a hurricane. Minimal fluctuations in intensity occurred before the storm made landfall near Panama City, Florida, on June 19. After moving inland, Agnes rapidly weakened and was only a tropical depression when it entered Georgia. Thereafter, weakening slowed as the storm crossed over Georgia and into South Carolina. However, while over eastern North Carolina on June 21, Agnes re-strengthened into a tropical storm, as a result of baroclinic activity. Early the following day, the storm emerged into the Atlantic Ocean before re-curving northwestward and making landfall near New York City as a strong tropical storm. Agnes quickly merged with a non-tropical low pressure system on June 23.