The aim of study was to determine the effect of barn climate conditions on milk yield and milking frequency in automatic milking system (AMS). In a period of 3 years, 24 farms with AMS were monitored. The monitored parameters were the milk yield (l.cow-1.day-1), and the milking frequency.cow-1.day-1 in AMS. These parameters were evaluated depending on air temperature (Ta), and relative air humidity (Rh). The average daily milk yield reached the highest values in the temperature range of 15-25 °C (32.18 ± 4.68 l. cow-1).