Why Weather Changes Can Cause Window Mist
If you’ve noticed your double-glazed windows fogging up after a storm or during sudden temperature drops, you’re not alone. Homeowners across Leeds, Glasgow, and Bristol often report this phenomenon, particularly in the colder months. But what’s really going on behind that mist?
Understanding the Science Behind Window Fog
Double-glazed windows are designed to insulate your home by trapping an inert gas (usually argon) between two panes of glass. When the window seal fails, moist outside air can seep in. During temperature fluctuations or after a storm, the pressure changes and cooling can cause that trapped moisture to condense rapidly, appearing as fog or mist between the panes.
Top Causes of Storm-Related Mist
- Pressure Changes: Rapid weather shifts, such as those following a heavy storm, can affect the air pressure inside older or weakened sealed units.
- Thermal Expansion/Contraction: Repeated expansion and contraction of the window materials due to heating and cooling weakens the seals over time.
- Water Ingress: High winds driving rain into failing sealant or frames can introduce moisture into the unit.
Is It a Serious Problem?
Misting between the panes isn’t just a cosmetic issue. A foggy window is a sign that your sealed unit has failed. Once that happens, the window loses its insulative properties, leading to:
- Inefficient heating and higher energy bills
- Reduced clarity and light transmission
- Potential for long-term mould and moisture build-up inside your home
Solutions for Misted Windows
Unfortunately, once the seal has failed, cleaning the inside of the panes isn’t an option. Instead, you’ll need a professional repair – usually the replacement of the insulated glass unit (IGU) within the existing frame.
Why Choose Professional Help?
DIY fixes, like temporary defogging sprays or drill-and-vent kits, rarely offer lasting results. A professional will correctly diagnose the issue and ensure the new unit is properly sealed and thermally efficient – especially important in the unpredictable UK climate.
Prevention Tips for the Future
- Have older windows inspected annually
- Install trickle vents to manage moisture levels inside
- Choose A-rated replacement units with warm-edge spacers
- Promptly repair damaged seals or frames
Get Help with a Misting Problem
If you’ve noticed persistent fogging after a storm or temperature shift, it could be a sign you need to replace the unit. At Get My Windows Fixed, we specialise in replacing failed double-glazed units across the UK, helping you restore clarity, comfort and energy efficiency.