Winter locksmith problems: cold weather and stiff locks

Locksmith call-outs noticeably increase over the colder months, and it's rarely a coincidence — cold weather genuinely does make locks more likely to fail.

Why locks get stiffer in winter

Metal contracts slightly in the cold, which can make an already slightly worn lock noticeably stiffer to turn. Any moisture that's found its way into the mechanism can also freeze, jamming the pins or the multipoint mechanism entirely.

UPVC doors and cold weather

UPVC frames can contract in the cold too, subtly shifting the alignment between the door and the keep in the frame — the same issue that causes a door to need lifting and pushing to lock, but more noticeable in winter.

Simple prevention

• A light coating of PTFE-based lock lubricant before winter sets in — avoid oil-based lubricants, which attract grit
• Wipe visible moisture away from the lock face after heavy rain
• Get a stiff lock looked at in autumn rather than waiting for it to fail completely in January

If it's already jammed

Avoid forcing a stiff key — it's one of the most common ways keys snap in winter. If a lock won't turn smoothly, it's worth having it looked at before relying on it in genuinely cold conditions.

A five-minute check before winter is a lot cheaper than an emergency call-out during it.