<P> The climate of the Red Sea is the result of two monsoon seasons; a northeasterly monsoon and a southwesterly monsoon . Monsoon winds occur because of differential heating between the land and the sea . Very high surface temperatures and high salinities make this one of the warmest and saltiest bodies of seawater in the world . The average surface water temperature of the Red Sea during the summer is about 26 ° C (79 ° F) in the north and 30 ° C (86 ° F) in the south, with only about 2 ° C (3.6 ° F) variation during the winter months . The overall average water temperature is 22 ° C (72 ° F). Temperature and visibility remain good to around 200 m (656 ft). The sea is known for its strong winds and unpredictable local currents . </P> <P> The rainfall over the Red Sea and its coasts is extremely low, averaging 0.06 m (2.36 in) per year . The rain is mostly short showers, often with thunderstorms and occasionally with dust storms . The scarcity of rainfall and no major source of fresh water to the Red Sea result in excess evaporation as high as 205 cm (81 in) per year and high salinity with minimal seasonal variation . A recent underwater expedition to the Red Sea offshore from Sudan and Eritrea found surface water temperatures 28 ° C in winter and up to 34 ° C in the summer, but despite that extreme heat the coral was healthy with much fish life with very little sign of coral bleaching, with only 9% infected by Thalassomonas loyana, the' white plague' agent . Favia favus coral there harbours a virus, BA3, which kills T. loyana . Plans are afoot to use samples of these corals' apparently heat - adapted commensal algae to salvage bleached coral elsewhere . </P> <P> The Red Sea is one of the saltiest bodies of water in the world, owing to high evaporation . Salinity ranges from between ~ 36 ‰ in the southern part because of the effect of the Gulf of Aden water and reaches 41 ‰ in the northern part, owing mainly to the Gulf of Suez water and the high evaporation . The average salinity is 40 ‰ . (Average salinity for the world's seawater is ~ 35 ‰ on the Practical Salinity Scale, or PSU; that translates to 3.5% of actual dissolved salts .) </P> <P> The salinity of the Red Sea is greater than the world average, by approximately 4 percent . This is due to several factors: </P>

What is the salinity of the red sea