The role of education in promoting global warming awareness is important to enable students to understand and address the impact of global warming. The use of Internet of Things (IoT) with collaborative learning strategies can enhance students� understanding of global warming. This study aimed to develop an IoT-based smart weather system enhancing the critical thinking skills of elementary students. It consists of weather-measuring sensors that capture data on temperature, humidity, air pressure, light intensity, and altitude. The data is stored in the Blynk cloud and displayed on smartphones. The IoT devices are placed in three different geographic locations. This paper presents the system design, including the system architecture and user interfaces. The data captured by the IoT sensors from the three measurement sites form the foundation to promote the development of collaborative learning. This result implies the need for teachers to creatively establish learning strategies in various subjects to improve students� critical thinking skills. © 2022. Dwi Sulisworo et al; published by UIKTEN. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 License.