Khamsin,[1] chamsin or hamsin (Arabic: خمسين ḫamsīn, meaning "fifty"), more commonly known in Egypt and Israel as khamaseen (Egyptian Arabic: خماسين ḫamāsīn, IPA: [xɑmæˈsiːn] ⓘ), is a dry, hot, sandy local wind affecting Egypt and the Levant; similar winds, blowing in other parts of North Africa, the Arabian Peninsula[citation needed] and the entire Mediterranean basin, have different local names, such as bad-i-sad-o-bist roz in Iran and Afghanistan, haboob in the Sudan, aajej in southern Morocco, ghibli in Tunis, harmattan in the western Maghreb, africo in Italy, sirocco (derived from the Arabic šarqiyya, "eastern") which blows in winter over much of the Middle East,[2] and simoom.

The sand storms are reported to have seriously impeded both Napoleon's military campaigns in Egypt as well as Allied-German fighting in North Africa in World War II.

[citation needed] In the southern Levant it takes the shape of an oppressive weather front with hot temperatures, large quantities of dust impeding visibility, and strong winds during the night.

[2] Khamsin can be triggered by extratropical cyclones that move eastwards along the southern parts of the Mediterranean or along the North African coast from February to June.

"[7] This period roughly coincides with the Jewish Counting of the Omer, which also lasts for an interval of 49 days, between the springtime feasts of Pesach (Passover) and Savuot (Weeks), as well as the Christian Eastertide which Copts also refer to as khamaseen.