How long is AIRMET valid for?

How long is AIRMET valid for?

• A. 3 hours
• B. 12 hours
• C. 6 hours
• D. 24 hours

Answer: (C)

AIRMETs are valid for six hours. They warn about moderate weather phenomena that could affect flight, such as turbulence, icing, IFR conditions, or mountain obscuration, and are issued for designated regions every six hours with updates as needed. This six-hour window gives pilots a practical forecast period to plan routes and anticipate changes; if weather persists or worsens, AIRMETs can be amended or canceled earlier, or new advisories issued. For comparison, other advisories use different valid periods (SIGMETs are typically four hours, convective SIGMETs two hours), and forecast products like TAFs are 24-hour outlooks, but AIRMETs specifically follow the six-hour validity.

AIRMETs are valid for six hours. They warn about moderate weather phenomena that could affect flight, such as turbulence, icing, IFR conditions, or mountain obscuration, and are issued for designated regions every six hours with updates as needed. This six-hour window gives pilots a practical forecast period to plan routes and anticipate changes; if weather persists or worsens, AIRMETs can be amended or canceled earlier, or new advisories issued. For comparison, other advisories use different valid periods (SIGMETs are typically four hours, convective SIGMETs two hours), and forecast products like TAFs are 24-hour outlooks, but AIRMETs specifically follow the six-hour validity.