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 in the north and in the south, with only about 2 °C (3.6 °F) variation during the winter months. The overall average water temperature is . Temperature and visibility remain good to around 200 m (656 ft). The sea is known for its strong winds and unpredictable local currents.