Abstract: Based on the daily mean and minimum temperatures at 58 weather stations around the Bohai Sea region from 1961 to 2010, the frequency and intensity of cold wave were analyzed in terms of the national standard on cold wave, and the climatic characteristics of cold wave in a single station and in the whole study area were discussed. The results indicate that the regional differences of cold wave frequencies in a single station are significant. In general, the cold wave is in a decreasing trend from north to south around the Bohai Sea region, and the number of annual mean cold wave is 21 in Zhangbei station and it is the highest among all stations, while the number  is less than 2  in the stations of Beijing and Tianjin region. There are 233 regional cold waves in the recent 50 years and it appears mainly from September to April, especially in November, and it is in a significant decreasing trend. The frequencies of regional cold wave is the highest from 1960s to 1970s, while it decreases since 1980s and an abrupt change appears in 1983. The extreme strong regional cold wave is rare, and it is only twice in 1960s and once per ten years since 1970s. The regional cold wave decreases significantly under the global warming background around the Bohai Sea region, while the extreme strong cold wave events do not decrease.

Key words: Cold wave, Intensity, Frequency, Around the Bohai Sea region