Is it cold in Africa in winter?

In winter in Africa, we can be seen everywhere. Some places, such as places near the equator, are in Singapore, Asia, even if they are not in Africa. Malaysia and Saigon, Vietnam, in winter here, you only need to wear short-sleeved T-shirts. So in Africa near the equator, January is also very hot, so you don't need to wear sweaters. But in desert areas of Africa, such as Mauritania, it is also very cold at night. At the coldest time, it's only 7 degrees at night. But strangely, although the coldest time at night is 7 degrees, it is very hot at noon. When I used to work there, in January, when I went to town in the morning, the temperature was only 8-9 degrees at 8 o'clock, but by noon, the temperature had risen to 40 degrees. I wear a sweater and a thick coat when I go out in the morning, but I have to go shirtless at noon. How hot it is! Do you find it strange? In fact, Africa is not very hot. In Tunisia and Algerian countries in North Africa, heating is needed at home at this time. Every family has heating, which is more comfortable than our room in Zhejiang. Otherwise, the indoor temperature is only 13 degrees. Without heating, Zhejiang is the same in winter. If you sit at home, it will get colder and colder!