Abstract—It is important to analyze and comprehend outdoor environmental conditions to address air pollution problems. Accordingly, while remote sensing is suitable for analyzing global environment data, the Internet of Things (IoT) technique can help us analyze and comprehend local environment data. Moreover, considering how IoT-based outdoor environmental monitoring can operate for long periods in environments is necessary during difficulties in securing a power supply. Therefore, this study proposes an operation time-prolonging method for an IoT-based outdoor environment monitoring system by combining solar power, storage devices, and intermittent operation for stable operations in outdoor environments. With our proposed method, while solar panels provides power during the day, storage batteries provides power after sunset, with the sensor devices operating intermittently during this period. Furthermore, because the energy supplied depends on daylight hours, the proposed system has a sleep period that considers daylight hours when prolonging the system’s operation time. Consequently, the operation time of the sensor node during the adaptive sleep period control becomes 6.0 times longer than that without sleep period control, showing the effectiveness of the developed system. Hence, our results establish the effectiveness of the proposed adaptive sleep period control for prolonging the operation time of IoT network-based systems, indicating this finding’s usefulness for future research approaches.