A real-time local positioning system was used to track the spatial position and activity of a commercial dairy herd (c100 cows) in a freestall barn continuously at high temporal resolution. Bunching was determined using four different spatial measures determined on an hourly b100asis: herd full and core range size, mean herd inter-cow distance (ICD), and mean herd nearest neighbor distance (NND). Wall-mounted temperature sensors automatically recorded the ambient barn temperature (BT) continuously throughout the study period. A mean hourly measurement was calculated across all sensors (n = 26 sensors, where n = 22 recorded every eight seconds and n = four recorded every hour).