Icing Conditions Predictor

Assess potential aircraft icing conditions for flight planning.

Icing Temperature Ranges

TemperatureIce TypeSeverity
0C to -10CClear IceMost Severe
-10C to -15CMixed IceModerate-Severe
-15C to -20CRime IceModerate
Below -20CLight RimeLight

Understanding Aircraft Icing

Conditions Required for Icing

Aircraft icing requires: 1) Visible moisture (clouds, rain, drizzle), 2) Temperature at or below freezing, 3) Aircraft surface below freezing. The most severe icing occurs between 0C and -20C.

Types of Icing

  • Clear Ice: Forms when large supercooled droplets freeze slowly. Heavy, hard to remove. Most dangerous.
  • Rime Ice: Forms when small droplets freeze instantly. White, rough, easier to remove.
  • Mixed Ice: Combination of clear and rime ice.
  • Frost: Forms on cold-soaked aircraft. Must be removed before flight.

Freezing Rain/Drizzle

Supercooled Large Droplets (SLD) - including freezing rain and freezing drizzle - can cause rapid ice accumulation beyond the protected areas of the aircraft. This is a severe hazard requiring immediate exit from the conditions.

Effects on Aircraft

  • Increased weight and drag
  • Decreased lift and thrust
  • Increased stall speed
  • Control surface restriction
  • Engine/propeller ice accumulation
  • Pitot/static system blockage