Abstract. This study was carried out on a commercial dairy farm located in the South-Moravian region of the Czech Republic. Two video cameras (IP7330 and PZ6122, Vivotek Technology), located over cubicles below the ceiling, provided video recordings, which were taken in 15-min intervals from 02.00 to 08.00 (Period 1 – morning) and from 10.00 to 19.30 (Period 2 – afternoon) one day per week (i.e. on Thursday) from 2 July (week 27) to 15 October (week 42). Air temperatures and humidity were measured every fifteen minutes during the days of behavioural observations using three HOBO data loggers. In order to determine the spatial distribution of dairy cows, the research barn was visually divided into three sectors of equal size: A – closest to the middle of the barn, B – between and C – the edge of the stable. Inside the barn, air temperatures predominantly ranged between 22 °C and 30 °C during Period 2, while in Period 1 they were lower by 5 °C to 11 °C. During Period 1, dairy cows were distributed quite evenly among sectors. Since week 29, however, the number of cows in sector A began to increase in Period 2 and did not return to the normal distribution pattern before week 42. Interestingly, the crowding was observed only during Period 2 and not in Period 1. Crowding began to appear when average daily temperatures increased to 20 °C.