Weather and air quality play an important role in determining environmental pollution. Fluctuation of these parameters not only causes environmental pollution but also causes severe injuries to human health. With the emergence of the Internet of Things (IoT), sensor-based weather devices with easy observation facilities started to develop. In this regard, this study focused on developing an IoT-based portable weather monitoring gadget that can measure weather and air parameters which are more often required in our day-to-day life. The proposed system is capable to measure temperature, pressure, humidity, altitude, PM2.5, PM10 level, VOC, and CO level. It consists of a portable display and a mobile app with a thing speak cloud platform. Further, the system has a Wi-Fi and GSM connection to communicate data. A mobile application was developed to monitor the readings in real-time which are stored in the cloud platform. The developed hardware was carefully calibrated in the national meteorological department to make sure our system is practically usable. Compared to existing models, our prototype is very handholdable, easily installable which does not require trained technicians, and is easily maintainable. Also, it is possible to access the data from anywhere in the world through Wi-Fi connectivity, and possible to make data visualization and analysis. On the other hand, it is very difficult to find a single, portable size, and low-cost device to collect all these parameters together. Nonetheless, our prototype has the potential of connecting with multiple similar devices to create a larger IoT network grid. Overall, our proposed product has a combination of weather and air quality parameters in a portable and handholdable size with low-cost and low power consumption which other devices do not have according to the latest literature.