Aviation abbreviation
Altimeter setting to sea level
QNH Pressure
At a glance
Meaning of Altimeter setting to sea level
The altimeter pressure setting used to indicate barometric altitude above mean sea level.
More about Altimeter setting to sea level
Correct QNH gives an indication close to aerodrome elevation when the aircraft is on the relevant reference surface.
It differs from QFE and from the standard setting used for flight levels. Temperature and other effects can still make indicated altitude differ from true geometric altitude.