During May and June of 2003, the US Army Night Vision and Electronic Sensors Directorate (NVESD) and the Ohio State University (OSU) measured the thermal behavior of mines in an arid site. Thermistors were placed in contact with both surface-laid mines and native stones and monitored from before sunset until well after sundown. Measurements of local vegetation and measurements of the surrounding soil at 2.5 and 5 cm depths were also performed. A tripod-mounted MWIR sensor was used concurrently to collect high-resolution images to identify and understand the underlying phenomena. Data were collected during both clear, sunlit conditions and during an overcast day, but because of space limitations only data acquired under the (more typical) clear conditions are described here. The results contain a number of findings. First, local soil properties appear to have important implications for the apparent mine contrast. The same type of mine at locations only a few meters apart can show significantly different contrast with the native soil. Second, natural phenomena can be a significant clutter source. The temperature of vegetation can be similar to that of mines, and a small plant will occasionally produce a signature with a shape similar to that of a surface mine. Native stones are also a source of false alarms, but they tend to show somewhat less contrast. Third, at certain times, mines are best viewed with a low-elevation angle sensor. The construction of some mines causes the temperature of the side walls to be significantly different from that of the top surface at those times. Finally, disturbing the surface of desert soil through excavation, vehicle traffic or even repeated pedestrian traffic is often sufficient to produce a strong thermal signature. This fact could be used to advantage to detect buried mines in desert environments.