The Temperature Data Logger is an open-source, Arduino-based device designed for recording and monitoring temperature data in agricultural settings. It utilizes an Arduino Uno microcontroller, an Adafruit data logging shield, and a TMP36 temperature sensor to capture temperature readings, which are stored on an SD card for later analysis. The project emphasizes simplicity and expandability, making it accessible for users new to electronics and programming. Potential enhancements include adding an LCD display or integrating relays to control greenhouse heating systems. This tool is particularly useful for farmers interested in tracking temperature variations in environments like greenhouses or under row covers.