When a cloud passes by, we receive less sunlight at the Earth’s surface. After the cloud passed, extra light reaches the surface. Understanding the pattern of light and shadow is important for detailed weather forecasts and predictions of solar energy production. Therefore, I will model sunlight for periods of several days and compare the results to observations. I will investigate three very different locations: the Netherlands, Barbados and the Amazon. The aim of this research is to model how clouds and aerosols impact light at the Earth’s surface on a locale scale in a simple and realistic way.