What happens if it rains on a newly painted exterior surface before the paint has completely dried?

The effect of weather conditions is extremely high in exterior paint applications. It is essential that the surface to be painted is dry, the surface temperature is above + 5ºC and the ambient temperature is +25º C. In external wall applications carried out at very high or very low temperatures, some problems may arise in the paint both during and after the application. In particular, the rain falling shortly after the paint has been applied causes the paint on the surface to be washed. The reason for the occurrence of this problem is that the paint transferred to the surface has become wet due to the rain since it has not dried completely and the paint starts drooping on the wet surface. For the solution of the problem, it is essential that the weather condition is better and the paint is re-applied after the surface has completely dried.