Tourism is a major part of the global economy which is heavily affected by weather. Therefore, it is very important to investigate the climatic conditions of a region in terms of the physiological comfort of tourists and to determine suitable periods for tourism elements, including planning, implementation and stay of tourists, especially in the hot and dry climates of the south of the country. In this study, we examined the spatial-temporal distribution of tourism comfort climate along the southern coastal regions of Iran in four provinces: Khuzestan, Bushehr, Hormozgan, and Sistan and Baluchestan, which are among the major ecotourism destinations. This research is descriptive-analytical in nature, aimed at examining climatic conditions and determining suitable times for tourism along the southern coasts of Iran. According to the results of tourism climate index during the years 1990-2022, the most favorable weather conditions for tourism in the region are in \months of November, December, December, February and March. In addition, the results of the neurotic pressure index showed that the most favorable time for tourism in the southern coasts of Iran can be seen in the months of November and March, and the results of the effective temperature index also indicate that the most suitable The months for tourists to visit this area are November, December, February and March. Therefore, among the studied indicators, the favorable and common months for tourism can be seen in November and March. The results of the present study, considering the climatic conditions of the southern coasts of the country, help decision makers and tourism planners to determine the optimal time for tourism and the presence of visitors in this region by choosing the appropriate climate index. It also improves our understanding of the correlation of the tourism climate index with the time of presence and the number of visitors during different months of the year in the region so that managers can make more informed decisions and plan appropriately in order to implement the sustainable development of tourism in this region.