UK locksmiths are reporting a surge in callouts over the summer of 2026 as extreme heat causes doors to swell, stick or jam, leaving homeowners unable to open or lock them. The problem stems from basic physics: heat makes materials like uPVC and composite doors expand, causing them to bind against their frames, particularly on south-facing or dark-coloured doors that absorb more warmth. It is affecting households across the country wherever temperatures have been highest, adding another disruptive strand to the ongoing effects of prolonged hot weather.

Alan Hickman, a Bournemouth-based locksmith with LockRite, says he is now getting roughly double his usual daily call volume, while Shane Hales, a Master Locksmith Association-affiliated locksmith in Sidcup, has gone from four or five heat-related adjustments a week to around ten. The Master Locksmith Association's Steffan George notes that a Facebook post explaining the issue drew about 50 times the usual traffic. Wooden doors face the opposite problem, shrinking as heat draws out moisture, which can cause them to drop and strain their locks; experts advise calling a professional promptly rather than forcing a stuck lock, which can snap the key and lead to costlier repairs.