strong cold spell

The North is about to welcome a strong cold spell
On the evening of 19/1, the cold air mass of intense intensity will spill into the northern heat, the highest level of the day is only 17-18 degrees C.
The North received more cold spells, many places below 13 degrees Celsius
From November 29, the North continues to receive a strong cold spell, the lowest temperature can go down to 12 degrees Celsius in the plains and 6 degrees Celsius in the highlands.
Why is the climate warming but the winter is cold?
Summer ... hot record, but why is the winter cold record?