Frostfall means a sudden drop in temperature, the meaning is introduced as follows:

A. Frostfall Introduction:

Frostfall is the eighteenth of the twenty-four seasons, the last of the fall. Doo refers to the Hundred Days of the Sun yellow longitude of 210 °, in the annual calendar October 23 to 24 to cross the festival.

After entering the frosty season, the late fall scenery is obvious, and cold air is moving south more and more frequently. Frost does not mean frost, but rather a sudden drop in temperature and a big difference between day and night temperatures, and on average across the country frost is the time of year with the biggest difference between day and night temperatures.

Frost season, all things Bicheng, Bicheng into the 11th, Yang down into the ground, the yin gas began to condense, the weather gradually cold began to frost. As frost is the cold day and night temperature difference in the performance, so the frost named this, said the temperature plummet day and night temperature difference in the festival.

The frosty season is characterized by cold weather in the morning and evening, and hotter at noon, with a big difference in temperature between day and night, and autumn dryness is obvious. The main customs of the Frost Festival include enjoying chrysanthemums, eating persimmons, climbing up to a high altitude, and taking tonic.

Second, historical origin:

Frostfall is the last solar term of autumn, the transition from autumn to winter. Frost season, all things Bi into, Bi into the Hundred Days, Yang down into the ground, the yin gas began to condense. The cold weather begins with the frost. In the "Yi Zhou Shu Zhou Yue", the mid-air of the three months of autumn is the heat stroke, the autumnal equinox, and the frosty season.

Frost festival reflects the weather gradually become cold climate characteristics, not that into this festival will be frost, in fact, frost is not from the sky down, frost is the ground water due to temperature changes encountered in the cold air condensation, frost festival has nothing to do with frost.

Three, meteorological changes:

Frost season is characterized by cold weather in the morning and evening, the weather at noon is relatively hot, the temperature difference between day and night, autumn dryness is obvious. On the national average, frost is the biggest difference between day and night temperatures in a year, into the frosty season after the cold air activity affecting China more and more frequently, the temperature difference between day and night increased rapidly. The temperature fluctuation is more and more obvious especially in south China.

The frosty period generally lasts from late October to early November, as dry and cold air gradually reigns supreme, warm and humid air has been marginalized, and much of the weather that characterizes summer and early autumn withdraws, making the weather relatively simpler. Stronger windy and cooling weather often occurs around the start of winter, and some places cross over into winter in a relatively short period of time.