Aviation Colour Codes are based on four colours and are intended for quick reference only in the international civil aviation community; they are part of the ICAO International Airways Volcano Watch system (IAVW). The Aviation Colour Code reflects conditions at or near a volcano and are not intended to pertain to hazards posed at a distance or downwind by drifting ash. The codes range from GREEN to RED.

ICAO Colour Code

Status of Volcano's Activity


Volcano is in normal, non-eruptive state. Or, after a change from a higher level: Volcanic activity considered to have ceased, and volcano reverted to its normal, non-eruptive state.


Volcano is experiencing signs of elevated unrest above known background levels. Or, after a change from a higher level: Volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase.


Volcano is exhibiting heightened unrest with increased likelihood of eruption. Or: Volcanic eruption is underway with no or minor ash emission.


Eruption is forecast to be imminent with significant emission of ash into the atmosphere likely. Or: Eruption is underway with significant emission of ash into the atmosphere.

  • No labels

GeoNet is a collaboration between the Earthquake Commission and GNS Science.

about | contact | privacy | disclaimer | mobile

GeoNet content is copyright GNS Science and is licensed under a Creative Commons Attribution 3.0 New Zealand License