Icing Conditions
Last updated: April 20, 2026 · Maintained by Aviatr Editorial Team
What is Icing Conditions?
Icing conditions exist when visible moisture (clouds, rain, drizzle) is present at temperatures between +10 and −20 degrees Celsius, with the most severe accumulation typically occurring between 0 and −15 degrees. Accumulated ice rapidly degrades lift, increases drag, and can block control surfaces and engine inlets during flight.
How is Icing Conditions used?
Pilots flying in icing conditions must have certified anti-ice and de-ice equipment (boots, heated surfaces, pitot heat) and must be trained in their use. Light single-engine aircraft are typically prohibited from flight into known icing. Before every flight the METAR and TAF are checked for visible moisture at forecast temperatures; any cloud layer in the relevant band is considered an icing risk. Icing types are categorized as rime, clear, or mixed — clear ice from supercooled large droplets is the most dangerous because it forms quickly and follows the contour of the wing. Structural icing affects takeoff performance, climb rate, and stall speed; induction icing can starve the engine of air. EASA certifies aircraft for 'flight into known icing' (FIKI) only when they carry the full required equipment suite and the crew holds the relevant ratings. National met services mark icing risk zones on forecast charts so pilots can plan routes around them.