Definition
An in-flight weather advisory issued by the National Weather Service to alert pilots of weather conditions that may be hazardous to aircraft, particularly those flown by less experienced pilots or aircraft with limited capability. AIRMETs cover moderate icing, moderate turbulence, sustained surface winds of 30 knots or more, widespread ceilings below 1,000 feet and/or visibility below 3 miles, and extensive mountain obscuration.
Plain English
A weather warning for pilots about conditions that are bad enough to be a problem, but not extreme. Things like rough air, ice on the wings, strong surface winds, low clouds, or poor visibility.
Context Anchor
Pilots encounter AIRMETs during preflight weather briefings, on aviation weather websites, and in flight-planning apps before choosing a route or deciding whether to go.
Derivation
Built from 'AIRmen's METeorological information.' The word 'meteorological' comes from the Greek 'meteoron' meaning 'thing high up' — the same root as 'meteor.' It refers to anything happening in the atmosphere, which is why weather science is called meteorology.
Why Pilots Care
Pilots review AIRMETs to assess whether a planned route remains safe or requires changes to avoid moderate hazards.
Intuition Check
Do not read an AIRMET as a flight clearance or a command not to fly. It is an official weather advisory that tells the pilot about conditions that may require caution, planning, or avoidance.
Example Sentence 1
During his preflight briefing, the pilot noted an AIRMET for moderate turbulence below 12,000 feet along his route.
Example Sentence 2
An AIRMET for IFR conditions was active over the mountains, prompting the pilot to file an alternate route.