This data package contains 30-minute standard meteorology and ancillary data collected at an eddy covariance tower in the Tromble Weir Watershed area of the Jornada Basin in southern New Mexico, USA. These data are used to quantify the water and energy balances in a small experimental watershed, including observational studies to calculate groundwater recharge as a water balance residual, to build relations between soil moisture state and ET flux, and to quantify land-atmosphere interactions and improve our understanding of the eddy covariance method. Additionally, they have been used in modeling studies as a validation of model performance. This file presents the ancillary data collected at the eddy covariance tower, excluding the 20Hz flux measurements that are archived at Ameriflux (site US-Jo2; link provided in Methods section). This includes soil moisture and temperature at 4 depths, air temperature and pressure, humidity and vapor pressure, ground heat flux, incoming and outgoing longwave and shortwave radiation, photosynthetically active radiation for a subset of the study period, and surface soil temperature. Instrument descriptions and detailed procedures are found in the references listed in the Methods section of this package. This is an ongoing dataset that will be updated annually.