In this paper, paddy storage in a warehouse where temperature is controlled by air-conditioning was monitored and studied, in Northern China. During the summer, using air-conditioning temperature control technology, the warehouse temperature and the average grain temperature on the surface can be effectively controlled below 22 ℃, but the temperature at different locations of the same grain layer varies greatly. The grain temperature in local areas near the surface of the grain pile, the west wall, and the south wall are still above 25 ℃. Affected by the high temperature of the external environment in summer, the temperature difference between the center of the grain pile to the side wall is more than 10 ℃, and there is water migration happening caused by “cold heart and hot skin”. Moisture and temperature tend to rise at a distance of 0.5 m from the surface of the grain pile and the side wall of the warehouse, which makes it a key place where mold is easy to grow. At the same time, it is also the location where the germination rate decreases and the fatty acid value increases. Therefore, in the process of temperature-controlled grain storage, it is necessary to strengthen the monitoring of the grain condition on the surface of the grain pile and the side wall of the warehouse.