Passive defense based on climatic elements can be as a strategy for creating limited environmental conditions to deal with external threats. The Persian Gulf region as one of the strategic areas that need to be evaluated from the perspective of defense. This study seeks to answer these questions that what are the climatic conditions in the northern Persian Gulf from the perspective of passive defense? Which parts of the Persian Gulf and its northern coastline have high potential for the climatic defense? In order to answer these questions, the authors of this study, used various climatic elements, climatic conditions of Persian Gulf for evaluating 12 synoptic stations and using from 15 climatic elements, including the absolute minimum and maximum temperature, minimum temperature, maximum and minimum relative humidity, days with thunder and dust, cloud, visibility, maximum rainfall, barometric pressure, wind speed and sunny hours, through Entropy & Copra methods. The results show that the province of Bushehr, especially in Bushehr & Kangan Jam stations, There are favorable conditions for passive defense and then Bandar Abbas, Qeshm and Kish also have the ideal conditions.