Currently, high-resolution mobile displays have been expanding rapidly, and thus graphical information is becoming increasingly important. During presentation of information, composition is an important factor affecting visibility of the information. Among the graphical information that is widely used in general, we focused on weather forecast figures being broadcast on TV as a typical example of simple and diversified composition. In this paper, we investigated a relationship between composition and visibility by manipulating length of lines separating isolated islands from main islands of Japan. Results of subjective assessment and eye movement measurement experiments demonstrated that the intensity of the division can significantly affect the visibility of weather forecast figures.