Dust haze fall within the definition of Lithometeors meaning suspension of extremely small, dry particles which are invisible to the naked eye but sufficiently numerous to give the sky an opalescent appearance as per this photo. In this case, the dust haze had originated from the Sahara Desert as a heat low which developed over the desert eventually moved towards the Central Mediterranean dragging convectionally lifted dust with it. Since the air was very dry, only high-level cloud formation was observed. The first thumbnail is the visible satellite imagery clearly indicating dust over the Maltese Islands whilst the second thumbnail indicated model reading of around 4900 milligrams of dust per square metre dragged northwards by a northnortheastward moving low pressure from Libya generated by intense solar radiation. Such sand haze is perfectly normal for the Maltese Islands in Spring.