Climate and Plant Geography of Kish Island

Kish Island is situated within a narrow strip of tropical vegetation in the Northern Hemisphere, lying between the Iranian Plateau to the north and the Arabian Desert to the south. Like other nearby islands, Kish is influenced by the semi-equatorial climate of this tropical growth zone. Its climate is classified based on a combination of rainfall and temperature, with an arid classification applied when annual rainfall is less than twice the average temperature. Kish’s climate is extremely dry and semi-equatorial overall, with an annual average rainfall of 6.3 mm and an average maximum temperature of 32.5°C.

The relative humidity and prevailing climatic conditions give Kish a maritime climate. For most of the year, except during the cooler seasons, the humidity remains above 60%. From November to May, temperatures are mild, fluctuating between 18°C and 25°C. According to available data, Kish experiences very warm to moderately warm weather with high relative humidity throughout the year, along with occasional rainfall that is typically short-lived but varies in intensity.

Distinct Climatic Features of Kish Island

Kish’s climate, influenced by its proximity to the Tropic of Cancer and the high-pressure systems of the subtropical zone, is inherently warm. The island’s location in the shallow, warm waters of the Persian Gulf contributes to its humid conditions, which persist for most of the year.

Rainfall on Kish primarily occurs between December and February, with November marking the start of the rainy season and May typically signaling its end. December rains are irregular and vary in intensity, while February rains are more consistent. On average, the rainy period spans a few hours over several days.

Historically, Kish’s tropical location and proximity to the Indian Ocean have allowed for occasional seasonal monsoons, particularly in August, when these systems are most active. These monsoons can bring short, intense summer downpours, sometimes exceeding the island’s total annual rainfall and often resulting in flash floods.

Aridity and Maritime Influence

The ratio of annual rainfall to evaporation is a critical indicator of a region’s climate. In areas where evaporation exceeds precipitation by a factor of 10 or more, such as central Iran or desert regions, the climate is classified as arid and dry. However, Kish’s unique location in the warm, shallow waters of the Persian Gulf results in high humidity levels nearing saturation, leading to its distinct maritime climate. This maritime influence makes the air consistently humid and oppressively warm for much of the year.