What Suffolk's record summer heat can do to exterior paintwork.

An exceptional summer

Suffolk had one of the hottest days in UK history this June.

On 26 June 2026, Santon Downham in Suffolk reached a provisional 37.3°C during an extraordinary spell of hot weather across East Anglia. The Met Office's verification process subsequently confirmed the official UK June record at 38.0°C in neighbouring Norfolk, but Suffolk remained one of the hottest parts of the country during an exceptionally warm month.

For owners of older and period properties, that sort of heat isn't just uncomfortable. Strong sunlight, high surface temperatures and repeated heating and cooling all put extra stress on exterior paintwork — particularly on timber windows, doors, fascias and other exposed joinery.

Why it happens

Strong sunshine is hard on exterior paint.

Exterior paint has a much tougher job than interior paint. Throughout the year it copes with sunlight, rain, moisture and continual changes in temperature. On a hot summer day, a painted surface in direct sunlight can become considerably hotter than the surrounding air.

Ultraviolet light also degrades paint over time regardless of temperature. Depending on the age and condition of the coating, that can show up as fading, a powdery or chalky surface, loss of gloss, and eventually cracking or flaking. Dark-painted surfaces are particularly vulnerable, since they absorb more solar radiation.

Why timber windows can suffer

Wood moves — the paint has to move with it.

Timber responds to changes in its environment. As moisture levels and temperature change, wood expands and contracts, and a good exterior paint system is designed to accommodate a degree of that movement while keeping moisture out.

Problems begin once a coating is already ageing or has lost its flexibility. Small cracks let moisture behind the paint, and once adhesion starts to fail you may see peeling, flaking or blistering — often first on the most exposed parts of a window. See our guide to preparing and painting timber windows for more on why some windows fail years before others on the same house.

Aspect matters

South- and west-facing paintwork deserves particular attention.

The direction a property faces makes a significant difference. South-facing elevations receive prolonged sunlight, while west-facing windows and doors can take strong afternoon sun when temperatures are already at their highest. On a period property, it's quite common to find paintwork on one elevation deteriorating considerably faster than the same paint system on a more sheltered side of the same house.

That's why exterior decorating shouldn't be approached on the assumption that every elevation needs repainting at exactly the same interval — the south and west sides usually need attention first.

Timing matters too

Don't paint simply because it's hot and sunny.

A run of sunny weather might seem like the ideal opportunity for exterior decorating, but very hot conditions aren't necessarily the best conditions for applying paint. Painting a surface that's extremely hot from direct sunlight can affect how the coating applies and dries. On particularly hot days, it can be better to work around a property following the shade rather than the sun, and to work to the manufacturer's stated application conditions for the paint system in use rather than simply picking a sunny day.

Getting it right

Preparation matters more than another coat.

If existing paint is beginning to fail, putting another coat over it won't solve the underlying problem. Loose and defective paint needs removing, surfaces properly prepared, defects dealt with and bare timber appropriately treated and primed before the finishing system goes on.

This matters especially on older sash windows and period joinery, where keeping good original timber is usually preferable to replacing it unnecessarily. A properly prepared and maintained timber window can go on doing its job for many years — see our guide to removing non-breathable paint for what's usually behind paint failing on a solid wall too.