Approximately more than 330 billion calibrated radiance measurements of the Moon had been acquired by Diviner over 7 years. Diviner data were routinely interrupted by pushbroom nadir mapping mode and had a small number of outliers during spacecraft or instrument anomalies. In one lunar day, the change of brightness temperature is relatively uniform at noon or throughout the night and abnormally severe in the morning or afternoon especially during sunrise and sunset. The Sinus Iridum bright temperature distributions of high spatial resolution and high coverage in six moments have been obtained by processing methods which include numerical simulation of bright temperature, elimination of singularities, piecewise fit and latitudinal direction correction. Remarkably, diurnal brightness temperatures are nearly equal to that calculated from the solar flux and vary depending on the distribution of topography range, material composition and channel photometric properties. The highest value appears in the direction of the slope towards the equator and the lowest value appears at the center of the crater where the elevation difference is the biggest. Nevertheless, nocturnal brightness temperatures mainly are sensitive to materials with differing thermophysical properties. Brightness temperature drop rate changes severly in the first half of the night and becomes gradually uniform in the latter half of the night. Results of the paper reveal the surface energy balance of the Moon, explain the complex and extreme nature of the lunar surface thermal environment. The results also provide a new comprehensive view of how regoliths on airless heavenly bodies store and exchange thermal energy with the space environment.