The sun angle is the angle at which sunlight strikes the Earth. The sun angle varies by location, time of day, and Earth's orbital position relative to the sun and determines the amount of heat energy received at any location on the globe.

The sun angle is used in construction to determine how to orient the building, and if the flexibility of orientation is not applicable, where to put the maximum glazing percentage in the project. This is done by producing radiation domes and run path diagrams like the one below.

Sun angles are also used in the calculation to determine potential photovoltaic power output and radiation.