QNH

Weather

The altimeter setting that makes the altimeter read altitude above mean sea level. With QNH set, the altimeter shows the aerodrome elevation while you are on the ground.

ATC and the ATIS give it in hectopascals, e.g. “QNH 1013” (inches of mercury in the USA). You fly on QNH below the transition altitude; above it you set the standard 1013 hPa and fly flight levels.

Also known as

altimeter setting

See also

QFE Flight Level MSL / AGL Transition altitude Q-codes

Learn ATC the practical way

Practise real radio calls, decode weather and fly ATC scenarios — with an instructor that talks back.