Increasing interest in monitoring the spatial variation of temperature at the animal level in swine finishing barns has led to the development of a new wireless data acquisition system. Previous studies used individual commercial data loggers placed in a protective container, then lowered into the animal pens. These traditional systems required significant effort to download each logger individually and to post-process the data into a time-synchronized file with all measurement points. The newly developed wireless system allows all measurement points to be simultaneously collected and logged to a single external data file. The specific project objectives include (1) develop a wireless sensor node capable of meeting the data transfer and sensor interface requirements of a swine finishing barn and (2) evaluate the performance of the wireless node through experimental testing. Each wireless node is preset with a specific ID which is logged with the sensor data to provide a definite indicator for the data’s source location within the barn. The individual nodes use a high accuracy thermistor for temperature sensing and are capable of transmitting one additional analog signal and eight digital signals to the data logger. The digital inputs were commonly used to collect fan activity data for ventilation monitoring. The additional analog channel can be used for other environmental sensing or for monitoring static pressure. When powered from a single 3.6 volt, 1200 mAhr battery, the wireless nodes have a usable life of 3.5 years when transmitting at a 5-minute sampling interval. This system was successfully developed and implemented for a 4-year study of swine finishing barns.