The climatic statistical characteristics of foggy weather along the Qiongzhou Strait coast are analyzed by using the surface observation and radiosonde data of Haikou Station from 1961 to 2006. The result shows that as far as longterm trend are concerned, the foggy days along the Qiongzhou Strait coast show a significant linear decrease trend, and the two climatic abrupt decrease periods are the early 1970s and the early 1990s. The fog days have good negative relation with diurnal minimum temperature; that is, the climate warming is the main reason for fog decrease. Fogs form more frequently in winter and spring, appearing from 06:00 to 07:00 in the morning and disappearing 1 to 2 hours later. Based on the reanalysis of data from NCEP from 1987 to 2006, three weather patterns of fog along the Qiongzhou Strait are summed up and forecasting indexes are put forward as well.