What Is a Freezing Rain Warning?
A Freezing Rain Warning is issued by Environment and Climate Change Canada when freezing rain is expected to create hazardous conditions.
Freezing rain is liquid precipitation that freezes when it comes into contact with sub-zero surfaces, producing a coating of clear ice known as glaze. Roads, sidewalks, vehicles, trees and power lines can quickly become coated in ice.
Even relatively small amounts of ice can make walking and driving dangerous. More significant or prolonged freezing rain can produce heavier ice accumulation capable of breaking tree branches, damaging infrastructure and contributing to power outages.
Related Warnings
| Warning or Alert | Description |
|---|---|
| Yellow Freezing Rain Warning | Indicates freezing rain is expected to produce hazardous conditions and moderate impacts, such as icy roads, sidewalks and difficult travel. |
| Orange Freezing Rain Warning | Indicates a higher-impact freezing rain event that may cause significant ice accumulation, dangerous travel, infrastructure damage or power outages. |
| Freezing Drizzle Advisory | Issued when persistent freezing drizzle is expected to create icy and hazardous surfaces. |
| Winter Storm Warning | Issued when multiple types of severe winter weather are expected together and may cause significant impacts. |
| Winter Storm Watch | Issued when conditions are favourable for severe winter weather to develop, but there remains uncertainty about its exact timing, location or severity. |
When Is a Freezing Rain Warning Issued?
A Freezing Rain Warning is issued when freezing rain is occurring or expected and is likely to create hazardous conditions.
Freezing rain develops when precipitation falls as liquid rain but encounters surfaces that are at or below freezing. The droplets then freeze on contact, allowing glaze ice to accumulate on exposed surfaces.
The potential impacts depend on factors such as the amount and duration of freezing rain, surface temperatures, wind and the amount of ice that accumulates.
Environment and Climate Change Canada now uses an impact-based, colour-coded warning system. A Yellow Freezing Rain Warning represents moderate impacts, while an Orange Freezing Rain Warning indicates conditions expected to cause greater impacts. Always read the full warning because expected conditions and impacts can vary considerably between events.
What Weather Conditions Should You Expect?
During a Freezing Rain Warning, expect rain that freezes when it reaches cold surfaces, gradually or rapidly producing a layer of ice.
Roads, sidewalks, parking lots, driveways, stairs and other untreated surfaces can become extremely slippery. Bridges, overpasses and elevated surfaces can be particularly susceptible to icing.
Ice may also accumulate on trees, power lines, vehicles and other exposed objects. During prolonged or heavier freezing rain, the additional weight can break branches and damage electrical infrastructure.
Freezing rain may occur alongside other winter precipitation, including snow, ice pellets or freezing drizzle, especially as temperatures change during a winter storm.
What Should You Do During a Freezing Rain Warning?
Avoid unnecessary travel when significant icing is occurring or expected and be prepared for rapidly deteriorating road and sidewalk conditions.
During a Freezing Rain Warning:
- Monitor the warning for expected timing and impacts.
- Avoid unnecessary driving when roads are icy.
- Allow additional stopping distance if you must drive.
- Walk carefully on untreated sidewalks, stairs and parking lots.
- Be especially cautious on bridges, overpasses and other exposed surfaces.
- Prepare for possible power outages during significant ice accumulation.
- Stay away from fallen power lines and report them to the appropriate utility or emergency service.
- Keep emergency supplies available if prolonged freezing rain is forecast.
- Continue monitoring forecasts because precipitation may change between rain, freezing rain, ice pellets and snow.
Conditions can change quickly when temperatures are close to 0°C, so continue checking updated forecasts and warnings throughout the event.
FAQ
A Freezing Rain Warning means freezing rain is occurring or expected and could produce hazardous ice accumulation on roads, sidewalks and other exposed surfaces.
Freezing rain is rain that freezes on contact with cold surfaces, forming a coating of clear or glaze ice.
Both freeze on contact with cold surfaces, but freezing drizzle consists of much smaller droplets than freezing rain. Persistent freezing drizzle can still create dangerous icy conditions.
A Freezing Rain Warning is associated with the more significant hazard posed by freezing rain, while a Freezing Drizzle Advisory is issued for persistent freezing drizzle that can make surfaces hazardous. Environment and Climate Change Canada classifies freezing drizzle among the winter weather events for which advisories are issued.
