What will cause the altimeter to read lower than normal?
What will cause the altimeter to read lower than normal? When the ambient (at altitude) temperature is colder than standard, the aircraft's true altitude is lower than the indicated barometric altitude. When the ambient temperature is warmer than the standard day, the aircraft's true altitude is higher than the indicated barometric altitude.
What does altimeter 29.92 mean?
When you set your altimeter to 29.92, you're flying at standard pressure altitude. This is the altitude of the aircraft above the standard datum plane, the theoretical location where at 15 degrees Celsius the altimeter setting will equal 29.92 inches of mercury.