Temperate rocky planets are being discovered around nearby stars but we know precious little about them aside from mass, incident stellar flux, and sometimes bulk density. To understand what these worlds are like we will need to know their climate. This will most likely require one or more expensive space missions, and it is worth studying which measurement suites best constrain simple climate models. I will describe how the changing color and brightness of an exoplanet, at both optical and thermal wavelengths, can be used to constrain its surface conditions and climate.