The ability of livestock to breed, grow, and lactate to their maximal genetic potential, and their capacity to maintain health is affected by climatic features. Climate affects animals both indirectly and directly. Indirect effects include those that climate exerts on grassland and crops, and on water availability. Additionally, climate may also affect survival of pathogens and/or their vectors, which may cause risks for health in animal and human populations. Analysis of meteorological and entomological data indicate that climate has favored invasion of Culicoides imicola into new regions of the Mediterranean basin where it was previously absent. The meteorological complex has not been studied precisely to determine the optimal combination for normal physiological functions and behavioral actions, health, welfare, and maximal performance of livestock. An index for measurements of environmental warmth and its direct effects in livestock is the Temperature Humidity Index (THI). The THI combines values of temperature and humidity an~ has been widely used as a bioclimatic indicator of thermal stress in livestock. Studies carried out within the CIRCE project permitted to characterize the Mediterranean basin in terms of THI and to establish its strong heterogeneity even if most of the area is at risk of heat stress for farm animals during summer. The same studies also indicated that the area will be also subjected to warming and extreme climate events, which may aggravate the consequences of hot weather in livestock. Comprehensive frameworks need to be developed to identify and target adaptation options that are appropriate for specific contexts.