Conditions on farms in the tropics can differ greatly depending on the season of the year. Characteristics such as disease prevalence, climate and availability of resources may not be constant all year around; however an acceptable level of animal welfare must be maintained throughout the year. Since it is neither practical nor economically feasible to perform several assessments per year, the purpose of this study was to define whether there were animal welfare issues at farms that were affected by the season to identify which season would present a greater risk to animal welfare, using a risk-based approach. Forty-five dual-purpose family farms in the Mexican tropics were assessed via the Welfare Quality® protocol. During the rainy season, 2.2% of the farms were classified as excellent, 57.8% as enhanced, 31.1% as acceptable and 8.9% as unclassified. In the dry season, 31.1% were classified as excellent, 68.9% as enhanced and none of the farms were categorized as acceptable or unclassified. Consequently, the season which presented the greatest risk to animal welfare of dual-purpose cattle raised under tropical conditions was the rainy season. However, there were management-related differences observed between the two seasons and the dry season also had some animal welfare threats. The fact that farms scored higher during the dry season is possibly the result of farmer awareness, leading to modification of their systems to provide animals with the necessary inputs to meet their production needs. If these modifications were not fulfilled, then welfare conditions might have been jeopardized.