Research into early childhood children's understandings in science has a long history. However, few studies have drawn upon cultural-historical theory to frame their research. Mostly, what is known has come from studies which have examined individual understandings of science concepts, without reference to culture, context or the collective nature in which children learn, play and live. The cultural-historical study reported in this paper examines the process of constructing understandings about clouds by kindergarten children (16 children, aged 4.5 to 6 years, mean age of 5.3 years) in an urban area of Greece. The research examines how children form relevant representations of clouds, how they conceptualize meteorological understandings in everyday life and how understandings transform through communications with others. The collection of the data was achieved through expanded, open-type conversations between pairs of children and one of the researchers, totalling 4 h of data. In depth analysis, using Rogoff's "three foci of analysis" (personal, interpersonal and context focusing) allowed for an examination of children's representations of clouds, how social and cultural factors framed thinking and gave insights into the processes of scientific thinking. On this basis, theoretical and methodological insights of this study of natural science by young children are discussed.