Abstract: Based on the analysis of the 52-year climatic data from four typical stations in Guangxi with the method of Morlet wavelet, the frequency features of the cold rainy weather in Guangxi have been investigated. The results show that (1) the average temperature between February and April in Guangxi increases gradually, the annual number of cold rainy days decreases gradually and the end dates of this kind of weather have become earlier; (2) the average temperature of Guangxi between February and April has the robust periods of 30 years, 18-19 years, 12 years and 3 years, and among them, the 30-year period is dominant. The annual number of cold rainy days has the robust periods of 30 years, 10 years and 2-5 years, but the dominant period is different meridionally with the value decreasing southward; (3) the robust period of the average temperature and the annual number of cold rainy days in Guangxi between February and April is consistent in the large-scale (30a) oscillations. These results show the advantage of the wavelet theory in the research on the frequency structure of the disaster weathers.

Key words: Guangxi, low-temperature rain, wavelet analysis, weather fluctuations