What is the time distribution of Yusong’s appearance?

Songs of rain are more common in mountainous areas and lake areas. Rainsongs appear from December to March in most parts of China. The distribution of average annual rainy days in China is characterized by more in the south and less in the north (but due to warm winters, South China rarely has temperatures close to zero, so there is neither hail nor rain); there are more humid areas and less dry areas (especially in southern China). Alpine areas have the most rainy days). Stations in China with an annual average number of rainy days of more than 20 to 30 days are almost all high mountain stations. The annual average number of rainy days at most stations in the plain areas is less than 5 days.

Songs of rain mostly appear within more than a month from early January to early or mid-February. The starting date is early in the north and late in the south, early in the mountainous areas and late in the plains. The end date is opposite. In mountainous areas with higher terrain, the rain starts early and ends late, and the rain period is slightly longer. For example, at Guangmingding in Huangshan Mountain in southern Anhui, the rain generally starts in early November and ends in early April of the following year, lasting up to 5 months. According to statistics, rainy weather in the Jianghuai River Basin occurs once in 2 to 3 years in the Huaibei region along the Huaihe River, and once in 7 to 8 years south of the Huaihe River. However, in mountainous areas, there is a big difference between valleys and mountaintops. Some valleys in mountainous areas have almost no rainstorms, while rainstorms occur almost every year in higher mountains.

In the 1960s, there was no rainstorm in Guangzhou, and Shanghai, Beijing, and Harbin only had 0.1, 0.7, and 0.5 days of rain each year on average. The station with the most rainy days in China is the Emeishan Meteorological Station, with an average of 141.3 days per year (167 days in the most years), followed by Jinfo Mountain with 70.2 days (93 days in the most years), and Green Slope in Badong, Hubei Province with 61.5 days. (maximum 90 days in a year), etc., all appear in the southern mountainous areas. Rainstorms in the north are neither numerous nor severe, especially in arid areas. The places with the most rainy days in the north are Huajialing, Huashan and Tianchi in Changbai Mountain, commonly known as Gansu Province. They have an average of 29.6, 19.8 and 18.5 days per year respectively, and they are also high mountain stations.

The season with the most rainy days is the warmer spring and autumn in northern areas with severe cold winters. For example, the month with the most rainy days at the Changbai Mountain Tianchi Weather Station is May, with an average of 5.7 days, followed by September. The average number of rainy days is 3.5. From December to March in winter, no rain occurs due to low temperatures. In the south, there are more cold winters. For example, the Emeishan Weather Station has an average of 26.4 rainy days in December and 24.6 days in January. In some years, it even rains every day in December, January and March. There is a rainy situation.