The enormous importance of the global ocean in the existence of life and its connection to the weather and climate regulation constitute fundamental elements of the Ocean Literacy Framework through which the understanding of basic ocean sciences issues is attempted. The main aim of this study is to assess the degree to which a carefully designed and properly implemented Teaching-Learning Sequence by a university research team, regarding the third principle of the ocean literacy guide entitled “The ocean is a major influence on weather and climate” affected pupils’ awareness. For the needs of the study, a questionnaire, comprising multiple-choice knowledge questions and attitudes and behavior statements following a Likert-type scale, was administered to a class of 17 third-grade primary school pupils before (pre-test) and after (post-test) the end of the teaching intervention. The Teaching-Learning Sequence which, among others, involved lectures, hands-on activities, and the production of educational material lasted 10 hours and was realized entirely at school. Results revealed a significant increase in pupils’ knowledge regarding the interaction between the global ocean and the weather and climate as well as in their attitudes and behavior, which could be attributed to the success of the design and implementation of the teaching intervention.