Climate and Plant Geography
Like other Persian Gulf islands, Kish - especially the islands of the Strait of Hormuz – is located in the narrow strip of land of specific growth tropical in northern hemisphere , with low Latitude, between the Iranian plateau (in the north ) and the deserts of Saudi Arabia (in the south). Apart from the specific geographical and local climate features, this island like other nearby islands such as Farur , Hendorabi , Shtvar , Lavan and even Qeshm being in the subtropical climate of this strip. On the basis of classification vital climates, in which the combined effect of precipitation and temperature, namely the ratio of the amount of rainfall in mm is defined as the temperature throughout the year and If rainfall is less than twice the temperature, this climate is considered as dry, Kish is a very dry area and its climatic conditions generally is arid and semi- tropical.
According to statistics, the average rainfall is 190 mm , (65 % in winter, 28 % in fall,14 % in the summer) - yesterday and today journal of Kish- mean annual temperature is 26.6 ° C.
Relative humidity conditions of the atmosphere and the Coefficient of climatic conditions of Kish, its weather has made marine. Except during the cold seasons, the moisture of the rest seasons is over 60 percent. In the months of November to May, Kish has mild weather and fluctuating temperatures is between 18-25 ° C.
The statistics available in the archives of Free Zone Organization of Kish indicate very hot, and to warm temperate weather with high humidity and sometimes the rain intensity is variable, and often short-lived in some days of the year.
Kish Island has the most sunshine hours - except for coastal areas of southeast and several other Persian Gulf islands - that is about 3,100 hours a year.
Kish in the usual classification of climate and on the basis of the elements of climate, especially being near the Tropic and in the subject of the high- pressure system of tropical weather and having the features of local position where is located in the warm and shallow waters of the Persian Gulf and the impact of climatic conditions, it is naturally warm. And, always, or most of the year the weather is humid.
Kish rainfall usually occurs during the months of December and March. A November rainfall is almost irregular and highly variable. But, the March regular rains, having situation relatively stable, with an average of about 31 mm. Relative estimates show that the beginning of the rainy season is usually around May and October and the end of the rainy season is almost in May and its total rainfall occurs in a few hours and in a few days .
A major reason of the Seasonal rains and the reason of spread and its time is related to the entering of air masses on the Persian Gulf waters. Regional rainfall in Persian Gulf mainly is due to the hyperbaric Centers of South wet systems (Sudanese) and low pressure centers of the Mediterranean systems and a wet flow related to the Indian Ocean and finally is influenced by seasonal rainfall regime. So rainfall is in full compliance with cold season and lack of precipitation is in full compliance with summer.
Since the island is in a vegetative strip of tropical. Naturally, the entering of Seasonal streams of Indian Ocean, especially in August – that is the peak of activity of this stream, having occasional rains in form of heavy showers. The amount of precipitation in summer is more than the amount of annual rainfall and is usually flooding.
The amount of annual rainfall compared with evaporation annually always is indicative of climate conditions of any region, and if the minimum amount of evaporation in any area is more than 10 times the amount of precipitation (such as deserts or the most central parts of Iran), this climate is dry, warm and cloudy. Even though, according to statistics, Kish has a mean average of annual rainfall, about 190 mm and annual evaporation is about 1650 mm, that is more than 9 times the rainfall and its weather should be cloudy, it has marine climate due to the fact that the local situation, namely being in shallow and warm waters of the Persian Gulf with high humidity close to saturation (in March 50 -55, in July, 60 percent) that caused of its sultry during the year