What’s the difference between glaze ice (from freezing rain) and black ice?

In winter forecasts you may hear two very similar-sounding terms. In Russian they’re «гололёд» and «гололедица» — and they describe different kinds of ice.

Glaze ice (ice on objects)

This is ice that coats objects: tree branches, power lines, roofs, railings, cars. It most often forms during freezing rain/drizzle when the air temperature is around 0 °C (or slightly below) and supercooled droplets freeze immediately on contact, creating a smooth, glassy layer.

Why it’s dangerous:

• it adds weight to branches and wires (breakage, falling trees/lines);
• it makes steps, handrails and any exposed surface extremely slippery;
• it can build up quickly.

Black ice / road ice (ice underfoot and under wheels)

This is a thin, slippery ice crust on the ground: sidewalks, roads, courtyards. It usually appears when:

• there was a thaw / wet snow / rain, then temperatures dropped and everything refroze;
• melted snow or water spread across the surface and later froze into a thin film.

It’s especially treacherous because it can be almost invisible (the classic “black ice” on asphalt).

Easy way to remember

• Glaze ice: ice on objects (branches, wires, railings).
• Black ice / road ice: ice on the ground (roads and sidewalks).

Quick safety checklist

• Walking: wear shoes with good grip, take shorter steps, keep hands free, avoid shiny “mirror-like” patches.
• Driving: increase following distance, avoid sudden steering/braking, slow down early; bridges and overpasses freeze first.

It’s especially treacherous because it can be almost invisible (the classic “black ice” on asphalt).