A slight chill means freezing into a ball.

Slight cold and severe cold freeze into a ball, which means that with the arrival of slight cold and severe cold solar terms, the weather begins to get colder gradually, and you can feel the biting cold wind when you go out in the morning and evening.

Slight cold and severe cold are the last two solar terms in the twenty-four solar terms, both of which indicate the change of temperature, in which slight cold is between "Erjiu" and "Sanjiu" and severe cold is during Sanjiu and Jiu Si periods.

According to the saying that "1929 didn't shoot, walked on the ice in 3949, watched willows along the river in 5969, opened the river in 79, brought geese in 89, and added 19 in 99, plowing cattle everywhere", it means that it was very cold in 3949, but the local weather forecast shall prevail.

The slight cold solar term means that the weather is cold, but it has not reached the extreme, because the slight cold is the 23rd solar term among the 24 solar terms and the fifth solar term in winter. At about 1.5 every year, the sun will move to 285 degrees of the yellow meridian, which marks the beginning of the coldest day of the year.

According to China's long-term meteorological records, due to the climate difference between the north and the south of China, the slight cold season in most parts of northern China is often colder than the severe cold season, and the slight cold usually lasts from February 9 to March 9.

Slight cold is the coldest time of the year in northern China, so there has been a saying in northern China since ancient times that "slight cold is better than severe cold, which is common but not rare".

However, for most parts of the south, the coldest days are in April and September, and April and September are often colder than March and September. April and September are cold solar terms, and the cold season in the south is usually the lowest temperature in the whole year, which is often colder than the slight cold season.