of μελτέμι meltemi), or meltem (Turkish) are the strong, dry north winds of the Aegean Sea, which blow periodically from about mid-May to mid-September.
Etesian winds are dangerous to sailors because they come up in clear weather without warning and can blow at force 7–8 on the Beaufort scale.
Etesians have been described since ancient times; their Turkish and the Modern Greek names are probably a loan from Italian mal tempo 'bad weather'.
Etesians are due chiefly to the deep continental depression centered over southwest Asia and blow from a direction which may be anywhere between north-east and north-west depending on local topography; etesian winds weather is ordinarily fine and clear, the northerly winds tempering the, at times, fierce summer heat of the region.
Historically, Philip II of Macedon timed his military operations so that powerful southern fleets could not reach him: their ships could sail north only very slowly while the etesian winds were blowing.