In Lleida (Spain) 13-14 year-old students investigated during 25 lessons if there is any relationship between weather (such as Temperature, Wind, Relative Humidity, pluviometry, etc.) and human behaviour or activities (such as listening to different types of music, doing sports, colours chosen for clothes, food consumption, etc.). Key data analytic skills were taught such as: define a research question, collect and consider data, interpretation of graphs, graphical data, interpretation of averages and drawing conclusions from data.