What Is the Best Time of Year to Paint the Exterior?

In Portugal, the best times to paint the exterior are usually spring and early autumn. The weather is dry, temperatures are mild and there is less risk of rain. Very hot summers and rainy winters bring more problems, but it is possible to paint in those months with care.

What paint needs in order to dry well

Exterior paints need a moderate temperature and a dry wall. Manufacturers state the minimum and maximum application temperatures on the label, and you should stick to them. If it is too cold or damp, the paint dries badly. If it is too hot, it dries too fast and can end up with marks.

Rain is the main enemy. A coat that is still fresh can be washed off or end up stained. Even after it has dried on the surface, the paint needs some time to harden.

Season by season

Spring: mild temperatures and longer days. It is a good time, but it can still rain, so check the forecast.
Summer: there are lots of dry days, but strong sun dries the paint quickly. Paint early in the morning or late in the afternoon, and avoid walls in direct sun.
Early autumn: usually dry, mild days. It is a good time, before the winter rain arrives.
Winter: more rain and more damp, and walls take a long time to dry. It is only worth it on dry days.

The climate in Lisbon and the surrounding area

In Lisbon, Cascais, Oeiras, Sintra and Amadora, summers are dry and hot and winters are mild, with spells of rain. This gives plenty of good windows for painting, but near the sea there is more damp and wind.

In parts of Sintra, for example, the hills bring more fog and damp. Walls dry more slowly. It is worth allowing more drying time and choosing your days carefully.

How to choose the day

Check the forecast for the painting days and for the following two or three days.
Avoid painting very early in the morning if there is dew on the wall.
Do not paint if the wall feels damp to the touch.
Avoid the hours when strong sun is shining directly on the wall.
Always leave some slack in the calendar for days lost to bad weather.

Planning ahead

In good seasons, such as spring, there is more demand for painters. If you want to paint at a specific time, it is worth arranging the work in advance. Good planning also lets you do the washing and repairs with time for the wall to dry.

If the job includes scaffolding, the erection also has to be booked. Work at height should always be done by professionals, with suitable equipment and on days without strong wind.

Tip: There is no point rushing. Painting a week later, in dry weather, gives a better result than painting now with a damp wall or rain on the way.