Paint will not dry below 8 degrees centigrade. If you paint below that temperature, the tints start to run out from the surface. So it’s advisable to do all the preparation first thing in the morning until the ambient temperature rises to about 10 degrees. Then follow the sun around the exterior. Interiors on cold days also present similar issues. The room may feel warm enough to paint, but the walls (especially older masonry walls) can be quite cold. And the paint will behave similarly. We use large room heaters in winter but care must be taken to avoid ‘sweating’ on the walls. That is, too much heat creating moisture. Painting above 35 degrees centigrade is also not advisable. The opposite happens here compared to cold weather. Paint dries too quickly, and you can be left with streaks in the finished coat or paint ‘grabbing’ leading to the same result. Metal is another issue. Metal is always colder or hotter than the environment. Roofs cannot be painted later than May or before September in the Central West generally.