Low-cost sensors for relative humidity, pressure, and ambient temperature have begun to be used regularly for different applications in which the measurement or control of systems or processes is required using an affordable technology. However, in most cases, reliable information about their performance, capabilities, and limitations is not available. In this work, we aim to establish a systematic comparison between different sensors widely used in conjunction with the Arduino platform, such as the DS18b20, DHT11, BMP180, and BME280 sensors. Laboratory and field trials were performed to determine linearity, accuracy, precision, resolution, response times, and response to loss of power. The results indicate that these devices, despite having a very low cost, can provide relatively reliable information, taking into account their manufacturing characteristics and the specific use required. In turn, this work offers useful information to choose the sensor that best suits a particular project.