Ambient air quality in livestock buildings is one of the most important factors affecting environmental pollution and global warming. Carbon dioxide (CO2), methane (CH4), ammonia (NH3) and hydrogen sulphide (H2S) are among the most hazardous gases in terms of human and animal health. The aim of this study was to determine the effect of hourly, daily and seasonal variations in the levels of hazardous gases, such as CO2, CH4, NH3 and H2S in a solid-floor confinement sheep barn; as well as the effect of climatic parameters, temperature (T), relative humidity (RH) and air flow (AF) on animal welfare. The correlation between hazardous gases and climatic factors in the barn was also determined. The study was carried out on a sheep farm between July 2012 and June 2013 in Konya (Turkey) where few data are currently available on this subject. Climatic data were measured at intervals of five minutes at different points during this study, while hazardous gases were measured at the same intervals during the experimental periods (10 days for each season). All data were analysed by one-way analysis of variance (ANOVA) and Tukey’s method was used to reveal intergroup differences. Cross-bilateral correlation between all data and different time periods was examined. There were significant differences between hourly and daily mean values of CO2, NH3, T, RH and AF. CO2 and NH3 levels showed a significant correlation with T and RH. Unfortunately, H2S and CH4 were below the level of detection in the study. Reducing the formation of these harmful gases, which have negative effects on animal production and cause environmental pollution, will be carried out with new sheep barn designs that take into account ambient air quality appropriate for animal welfare.