Causes of sultry weather on cloudy days

It is caused by high pressure (anticyclone). Please listen to me:

Low pressure or cyclone, high pressure or anticyclone are different descriptions of the same weather system. Low pressure and high pressure refer to the distribution of air pressure, and air pressure and anticyclone refer to air flow.

A cyclone is a horizontal vortex with a low central pressure and a high surrounding pressure. In the northern hemisphere, the air in the cyclone area flows counterclockwise, while in the southern hemisphere, it is just the opposite. At low altitude, air flows into the cyclone center from all directions, forcing the air in the center to rise. When the air rose to the sky, it flowed out around again. In this way, the lower atmosphere will continue to flow into the center from all directions to supplement the rising air in the center.

An anticyclone is a horizontal vortex with a high central pressure and a low peripheral pressure. In the northern hemisphere, the air in the anticyclone area flows clockwise, but in the southern hemisphere, it is the opposite. After the anticyclone flows out of the earth, the upper air is replenished from top to bottom, forming a downward flow to replenish the air flowing out from the near surface. Therefore, the existence and development of anticyclone is based on a circulation system connected by the vertical movement of airflow, which is consistent at low altitude and high altitude.

The weather under the control of anticyclone will be very stuffy, because the air in the upper air sinks and the air pressure near the ground rises.

Note: I called myself, so I'd better get extra points. Thank you.