Frost's Descent (Chinese: 霜降), the 18th solar term of the year, began this year on Oct 23 and ended on Nov 6. It begins when the Sun reaches the celestial longitude of 210°and ends when it reaches the longitude of 225°. Frost's Descent is the last solar term in autumn, and it is also the transition period from autumn to winter. After this day, the activity of cold air is frequent and it is deep autumn already. For more information, please read:8 things you may not know about Frost's Descent. [Photo by Wan Jin/Palace Museum]