and efficiency of flights. When flying in thunderstorms area, passengers and crew may encounter dangerous weather such as wind shear, bumps, hail, downburst, etc. In recent years, Fuzhou Changle International Airport has experienced a rapid growth for flight delays and return flight due to thunderstorms. In 2016, the number of flights affected by thunderstorms at Changle Airport was 729, taking up 38.4% of the total number of flights affected by the weather. The annual average thunderstorm of Fuzhou Changle International Airport is 27.3d which is considerably frequent and has a greater impact on flight. Thunderstorms vary greatly from year to year, and thunderstorms may occur throughout the year. As the temperature rises, thunderstorms frequency begin to increase. The main activity period of thunderstorms at Fuzhou Airport is from March to September. Thunderstorms appear most frequent in summer, with an average number of days of 13.5 days, accounting for 49.5 percent of the total number of thunderstorms in the year. Compared to other months of the year, the thunderstorms in June showed the highest number, with an average of 5.1d. Most are dry thunderstorms and are not prone to rainfall. Thunder mainly concentrated in the afternoon to the middle of the night, with the highest frequency occurring at 17: 00. Thunderstorms may occur in all directions of Fuzhou Airport, among them, west direction has highest frequency, followed by the northwest and southwest directions. This is because the eastern part of the airport is the ocean, the west is the mountainous area, and the convection over the mountains is stronger than the ocean. Visibility The average visibility in the first half of the year is less than 1000 meters. The number of days is significantly higher than that in the second half, accounting for 83% of the whole year. The visibility of the airport has obvious seasonal differences, showing the worst visibility in spring. See also List of airports in China List of the busiest airports in China References Airports in Fujian Transport in Fuzhou Airports established in 1997 1997 establishments in China