This is the student's text of one of the units of the Intermediate Science Curriculum Study (ISCS) for level III students (grade 9). The chapters contain basic information about weather, its measurement and predictions, activities related to the subject, and optional excursions. A section of introductory notes to the student discusses how to use the book and how the class will be organized. Data tables within the workbook format indicate where responses are expected. Illustrations accompany all instructions and the students are expected to select the proper equipment based on the illustrations. (SA)