The aim of this study was find out the influence of different level of ventilation outdoor individual hutches on thermal comfort of calves. The monitoring was carried out on one farm with Holstein calves in the time over nine months. The calves were housed in outdoor individual hutches with different orientation of the entrance to the windward side and leeward. The air temperature, air relative humidity and air flow, temperature-humidity index, cooling value of breeding environment in 72 calf hutches were determined during the experiment. The obtained data were evaluated by a general linear model in the program TIBCO Statistics. Based on the obtained results, it is possible to state that the location of the hutches and the regulation of air ventilation openings in the hutches have a significant effect on the thermal comfort of housed calves. The calves reared in hutches with the entrance located on the windward side were exposed to heat during the summer for a long time, while in the spring, autumn and winter to high cooling.