The average annual number of fog days in the past 50 years, and the daily fog observations in the past 10 years in Hefei were selected to analyze the area fog spatial and temporal characteristics. Detailed grid, ECMWF data for interpretation and application of autumn and winter fog are used. The results showed that: Hefei fog appeared slowly linear increase, accounting for 20% fog abnormal years; 91% fog occurring time during the morning hours 04:00～10:00, radiation fog accounting for 94%. In November and January, fog and dense fog occured most frequently. Foggy days in winter are more than that in summer, but in December is less fog. Fog and dense fog in Feixi County stations occured most frequently. Temperature, humidity, wind speed, cloud cover and radiation fog has good correspondence.