Weather servicesQuestion 382 of 934

For how long is a standard SIGMET valid?

  1. 1 hour
  2. 2 hours
  3. 4 hours
  4. 12 hours
Show answer

Correct answer: 4 hours

SIGMETs for tropical cyclones and volcanic ash are valid for 6 hours.

Source: Aeronautical Information Manual (FAA, Basic with Change 3, 9 July 2026), AIM 7-1-6 Inflight Aviation Weather Advisories, page 528

Practice weather services

Questions last reviewed: 18 October 2026