From the severe cold of March 9th to big data, is "March 9th" really the coldest in the whole year?

　　No shot in 1929, walk on the ice in 3949... @中国风险 According to the statistics of the average temperature during the "counting nine" period in the past 30 years, nearly four-fifths of the country's land is the coldest period in March 9 , forty-nine.

After the winter solstice, as the heat from the sun decreases, the heat stored on the ground also decreases day by day, and most of the north enters the coldest period of the year during the March 9 period.

Most of the south is colder in April and September, including the eastern part of the south of the Yangtze River and most of southern China.

Let's see when is the coldest time in your house?

　　(China Weather Weibo)