Roofed beef cattle barns with under-floor deep pit manure storage were studied for their gas concentrations. Ammonia and carbon dioxide levels were measured in three different barns during different seasons. The gas concentrations varied depending on the location within the barn and the season. Ammonia levels were higher over the manure surface compared to nose and floor levels. The differences in gas concentrations were influenced by factors like temperature, manure characteristics, and stocking density. This study shows that gas concentrations can vary between beef cattle barns, which can help in designing better models for gas emissions.