They relate because the further up you go, the colder it gets, and the air pressure decreases the further up you go. The altitude temperature and the air pressure both decrease, and that is their relationship. Altitude temperature decreases, the higher you go, and air pressure also decreases, the higher up you go. Therefore, the lower down you go, the higher the air pressure, and the higher the altitude temperature.
Hope this helps and have a nice day:)
