Air pollution is a major environmental issue that is harmful to the living organisms and climate. The increasing level of air pollution contributed by the release of dangerous air particles are seriously degrading visibility and causing a respiratory problem to many people. Installation of air quality monitoring system in critical areas to determine the trends of ambient air quality for prevention and corrective measures is necessary. Some existing systems are costly, require high maintenance and are not widely available in many areas. This paper presents a portable and light-weight air quality monitoring system using a wireless sensor network (WSN) to monitor the air quality in the outdoor environment and provide a remote access. Our proposed system monitors the major air pollutants which are carbon monoxide (CO), particulate matters with diameter less than 2.5 micron (PM2.5), and carbon dioxide (CO2) and records the temperature and humidity readings. LoRa technology is used to achieve the long-range data transmission and the transmitted data are then stored in the cloud server for future use and easy access. The air pollution index (API) is used as an indicator of the air quality to provide the status of the air quality. The finding of this paper indicates that the air in the rural area is less polluted than the air in the urban area, which is mainly contributed by the rapid economic development, vehicle exhaust fumes, and chemical discharge. © 2021 IEEE.