This investigation is an endeavor to propose an innovative indicator in order to eliminate the restrictions of similar indices. The Outdoor Tourism Climate Index (OTCI) elucidates whether or not the combination of different climatic elements, their compatibility with the climate at the travel origin, and the tourist's purpose of traveling is desirable for outdoor tourists, nature-based tourists, and the other tourists who undertake some activities in the open areas. OTCI was calculated for the outdoor tourists traveling from three different travel origins in Iran, including Tabriz, Shiraz, and Bandar Lengeh, to Bandar Abbas. The findings illuminated further accuracy and closeness to the reality of OTCI rather than Tourism Climate Index (TCI). Furthermore, as far as traveling to Bandar Abbas was concerned, the OTCI score of tourists from Bandar Lengeh (with similar climatic conditions to those at Bandar Abbas) was recognized to be higher than those from Shiraz and Tabriz (with more different climatic conditions).