One of the most critical parameters in agricultural production is environmental conditions. It is of vital importance to ensure and monitor suitable climatic conditions for various controlled agricultural structures and production systems such as greenhouses. To this aim, most data monitoring systems cannot be efficiently used due to high cost and insufficient technical knowledge. It is possible to design low-cost and scalable monitoring, control and data acquisition systems via open source hardware in order to monitor climatic data for agricultural practices in small enterprises and rural areas. In this study, a low cost system designed via open source hardware was tested under real conditions. Temperature and relative humidity were measured via the sensors in the system and sent to a data server through a wireless network. In addition, collected data was compared to reference devices for statistical analysis. The results suggest that these low-cost systems, which are designed via open source hardware, can be used as a data collection and decision support, system by agricultural enterprises.