This is a very common cloud all over the world. This specific cloud is low and flattened with base of around 400 metres in this instance. Specifically, the day was rather cloudy in places because of these clouds which were formed locally due to moist NorthEasterly wind coming from a long sea track. The geography of Malta (sloping gently from east to west with cliffs up to 250 metres on the west side of the Island) causes Northeasterly wind to ascend slowly over land area causing weak convective currents hence cumulus humilis. This happens only during stable weather conditions which was the case on this day. Otherwise, if any instability or low pressure is present, such wind quickly raises cumulonimbus clouds producing localized heavy showers.