Climatic characterisitcs of cold wave in Heilongjiang province from 1961 to 2012

Based on daily average temperature and the minimum temperature at 62 weather stations in Heilongjiang province from 1961 to 2012, cold wave at a single weather station was defined, and climatic characteristics of cold wave were analyzed. The results indicate that frequency of cold wave decreases significantly in recent 52 years, and it is in a good agreement with topography distribution. Frequency of cold wave is higher in the mountainous region than in the plain region. Cold wave appears mainly in November and December, seldom in September. Frequency of cold wave is higher in winter than in spring and autumn. Frequency of cold wave is in a decreasing trend in spring, autumn and winter in recent 52 years, except in autumn in Daxing’anling region.