SIGMET (significant meteorological information)

Weather

A SIGMET warns of specified observed or forecast en-route weather phenomena that may affect aircraft safety. The message defines the affected area, levels and validity period.

German term: SIGMET (Warnung vor signifikantem Flugwetter)
Abbr.: SIGMET

Phenomena include specified thunderstorm conditions, severe turbulence, severe icing and volcanic ash. A SIGMET is not a complete weather forecast or an aerodrome report. AIRMET is a different product for specified hazards affecting low-level flight, where issued. No SIGMET does not mean no hazardous weather exists.

In practice

Check whether the area, altitude band and time overlap your route, and allow room for uncertainty and movement. Use current official warnings alongside route forecasts and observations.

Related terms

Official sources

Content reviewed: 2026-11

For general information only. Always use official sources, your aircraft's flight manual and current national rules for flight decisions.