People dressed in shirts walk in Shanghai on Jan 4, 2015. Temperature surged to 15.6 degrees celsius in Shanghai on Jan 4, the highest this winter. [Photo/IC]

January 6 marks the 23rd solar term, Xiaohan, or Minor cold, which means the weather will quickly reach its coldest point. But Shanghai recorded 15.6℃ and Nanjing in Jiangsu province saw 17℃ on Jan 4, 2015, the highest temperature this winter.

The 24 solar terms, based on the Sun's position in the zodiac, were created by farmers in ancient China to help them in farming activities.