Structure and variability of temperatures in the tropical UTLS (~10-25 km) are studied based on Global Positioning System Meteorology (GPS/MET) observations. Mean structure and variability of the tropical cold point tropopause is examined, and much of the sub-seasonal variability in cold point temperature and height appears related to wave-like fluctuations, such as gravity or Kelvin waves. Correlations with OLR data (a proxy for tropical convection) shows the temperature response to transient convection, and reveals coherent wave-like temperature variations over ~12-18 km which are highly non-local in longitude. The GPS/MET data also show evidence of the stratospheric QBO.