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Freezing rain

Freezing rain is liquid precipitation that falls through subfreezing air near the ground and freezes on contact with exposed surfaces, forming a coating of glaze ice.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 27, 2026|2 min read| Fact-checked

Freezing rain is liquid precipitation that falls through subfreezing air near the ground and freezes on contact with exposed surfaces, forming a coating of glaze ice. It is distinct from sleet because the drops remain liquid until they reach the surface. Freezing rain can create hazardous travel conditions and damage trees and power lines. In Canada, it is a significant weather hazard during winter and shoulder-season storms, often causing dangerous roads, flight delays, and widespread power outages.

Formation

Freezing rain forms when snow melts in a warm layer of air above the surface and then falls through a shallow layer of below-freezing air near the ground. The droplets do not have enough time to refreeze before impact, so they freeze on contact with cold surfaces.

Characteristics

The precipitation is liquid in the air but turns into a thin, often transparent layer of ice after landing. The resulting glaze ice can build up on exposed surfaces and may be difficult to see.

Impacts

Freezing rain can make roads, sidewalks, bridges, and aircraft surfaces slippery or hazardous. Accumulations can also weigh down and break tree limbs and damage electrical infrastructure.

Freezing rain is closely related to sleet and drizzle, but it differs in the depth of the cold layer and whether droplets freeze before reaching the ground. Sleet consists of ice pellets, while freezing rain remains liquid until impact.

Key facts

  • Freezing rain is rain that remains liquid while passing through subfreezing air and freezes when it hits a surface.
  • The droplets are often described as supercooled because they stay liquid below 0°C.
  • It commonly produces clear glaze ice on roads, trees, vehicles, and power lines.
  • A significant accumulation of freezing rain is often called an ice storm.
  • The exact precipitation type depends on the depth of the warm layer aloft and the shallow cold layer near the ground.
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Canadian context

Freezing rain is a significant weather hazard in Canada, especially during winter and shoulder-season storms, because it can cause dangerous road conditions, flight delays, and widespread power outages.

Frequently asked questions

What is freezing rain?
Freezing rain is liquid precipitation that freezes when it touches a cold surface, usually creating a coating of glaze ice.
How does freezing rain form?
It forms when snow melts in a warm layer aloft, then falls through a shallow subfreezing layer near the ground and stays liquid until impact.
How is freezing rain different from sleet?
In freezing rain, drops stay liquid until they hit a surface. In sleet, the drops freeze into ice pellets before reaching the ground.
Why is freezing rain dangerous?
It can rapidly create very slippery surfaces and add weight to trees and power lines, increasing the risk of accidents and outages.
What is glaze ice?
Glaze ice is the smooth coating of clear ice left when freezing rain freezes on exposed surfaces.
What is the METAR code for freezing rain?
The METAR code for freezing rain is FZRA.

References

  1. Wikipedia — https://en.wikipedia.org/wiki/Freezing_rain
    Supports: Definition, supercooled droplets, glaze ice, METAR code FZRA, and ice storm terminology.
  2. Met Office — https://weather.metoffice.gov.uk/learn-about/weather/types-of-weather/rain/freezing-rain
    Supports: Explanation that freezing rain is liquid precipitation that freezes on contact and forms clear ice.
  3. National Weather Service — https://www.weather.gov/rnk/measure_icing
    Supports: Difference between freezing rain and sleet and the shallow cold-layer formation process.
  4. NAV CANADA — https://avmet.navcanada.ca/en/freezing-rain.aspx
    Supports: Definition, atmospheric setup, and conditions associated with freezing rain.
  5. National Weather Service — https://www.weather.gov/iwx/sleetvsfreezingrain
    Supports: Formation process, impacts, and the term ice storm.
  6. GLISA — https://glisa.umich.edu/freezing-rain/
    Supports: Surface freezing, dangerous icy layer, and the importance of event duration.