Temperature monitoring systems for data centers include a plurality of ceiling-mounted infrared sensor arrays. Each infrared sensor array includes a two-dimensional array of infrared emission sensors, and at least some of the infrared emission sensors have field of view patterns that project onto aisle faces of equipment racks that are mounted in rows in the data center. These systems may further include a controller that is remote from at least some of the infrared sensor arrays and that is in communications with the infrared sensor arrays, the controller configured to provide a two-dimensional thermal map of the aisle faces of the equipment racks based at least in part on temperature data received from the infrared sensor arrays.