What Snowfall Triggers a Plow? The 5 cm Threshold Explained

Snow & Winter · Published September 12, 2026

When you sign a snow removal contract in London, you'll agree on a "trigger" — the snowfall depth that sends the crew to your property. Understanding how triggers work helps you set the right one and avoid surprises.

The Standard: Around 5 cm

Most London snow contractors activate service at roughly a 5 cm accumulation. It's a practical threshold — below that, a light dusting usually doesn't need machinery, and above it, snow starts to pack down and get harder to clear cleanly. A defined trigger means you know exactly when the crew rolls.

Why Not Clear Every Flake?

Clearing at every 1 cm would mean constant visits and a much higher cost for little benefit. The 5 cm trigger balances a consistently usable driveway or lot against a sensible number of visits. During a long storm, crews make additional passes rather than waiting for it to end.

Commercial Triggers Can Be Different

High-priority commercial properties often set a lower trigger or a "clear before opening" rule regardless of depth, because a business needs safe access the moment it opens. A medical office can't wait for 5 cm. These custom triggers are written into the contract. See our commercial snow removal page for how commercial scopes are built.

Salting Has Its Own Trigger

Salting and de-icing often run on a separate trigger from plowing, since ice can form without heavy snowfall — think freezing rain or a melt-refreeze cycle. A complete contract addresses both snow clearing and ice control.

Setting Your Trigger

For most homes, the standard 5 cm works well. If you have mobility needs, a steep driveway, or you leave very early, a lower trigger or guaranteed early clearing is worth discussing. We'll set the right trigger for your situation — see our snow removal page.