What is the lowest temperature in history in Shandong and Yantai, Qingdao?

It's MINUS 20 degrees in inland areas and MINUS 15 degrees in coastal areas. But in recent years, due to the influence of warm winter, this kind of extreme weather is rare. All the year round, it is normal that the inland temperature is below zero 15 degrees and the coastal temperature is below zero 10 degrees. In 2005, the temperature in Taian, Shandong Province was-13 degrees for one week, which was the coldest I felt. I come from Taian, Shandong. Taian is located in the middle of Shandong Province, belonging to the mountainous area of Luzhong. This is the best place to accurately predict the low temperature. A lot of support!