Last updated: 15 October 2026
A padlock that opened all summer can seize solid in January. Cold does not just make metal brittle — it turns trapped moisture into ice and thickens old lubricant into glue. Five minutes of preparation in autumn saves a snapped key and a cut lock in winter.
Why winter kills padlocks
- Water in the keyway freezes and jams the pins.
- Old oil thickens in the cold and attracts grit, which grinds the mechanism.
- Condensation forms inside a lock that goes from warm to cold and back, rusting the barrel from the inside.
- Road salt and sea air attack a plated body and a soft shackle.
Six steps to winter-proof a lock
1. Dry it out
Before the first frost, open the lock and let it dry indoors for a few hours. Any water already inside will otherwise freeze.
2. Use graphite, never oil
Puff graphite powder into the keyway — it lubricates without attracting dust or thickening in the cold. Oil feels smoother in summer and turns to varnish in winter.
3. Fit a cover over the keyway
A weatherproof cover is the single most effective cold-weather upgrade. It keeps rain, snow and grit out of the mechanism entirely. Locks with a covered keyway survive winters that ruin open ones.
4. Lubricate the shackle, not just the keyway
A drop of a dry-film or PTFE lubricant where the shackle enters the body keeps it moving when frost sets in. Avoid thick grease.
5. De-ice safely
Never pour boiling water on a frozen lock — the thermal shock can crack it, and the water refreezes. Use a hand warmer, a warm (not hot) cloth, or a squirt of isopropyl alcohol to melt the ice.
6. Keep one lock indoors as a spare
If a gate lock does freeze, a spare kept warm indoors means you are never locked out of your own property.
Combination or key in winter?
This is where the two types part company. A combination dial can freeze solid, and you cannot de-ice it without seeing the numbers. A keyed lock tolerates cold far better — the key pushes through a little ice, and graphite keeps the pins free. For a gate or shed that stays outdoors all winter, a keyed lock is the safer choice. Our keyed padlocks are built around a brass cylinder that shrugs off frost.
Choosing a lock that survives the cold
- Stainless or marine grade for coastal or salty sites — see the outdoor padlock range.
- Hardened shackle — cold makes soft steel brittle, so a hardened shackle is both stronger and less likely to snap.
- Covered keyway — the cheapest insurance against a winter seizure.
If your gate hardware is exposed, a surface bolt gate lock with a sealed, covered mechanism often outlasts a bare padlock in the same spot.
Frequently asked
How do I unfreeze a frozen padlock? Warm the body gently with a hand warmer or a warm cloth, or use isopropyl alcohol. Never use boiling water, which cracks the lock and refreezes.
Why does my combination lock stick in winter? Moisture in the dial freezes. Switch to a keyed lock for exposed outdoor use and keep the keyway graphited.
Is oil or graphite better for a padlock? Graphite. Oil thickens in the cold and traps grit; graphite stays dry and works at any temperature.
Can a padlock rust from the inside? Yes — condensation rusts a barrel that never dries. A covered keyway and dry storage prevent it.