This data set contains meteorological observations at 36 sites throughout the Small Regional Study Area (SRSA) of the NASA Cold Land Processes Field Experiment (CLPX) in Colorado, USA. Identical meteorological towers were located close to the four corners of nine 1 km x 1 km Intensive Study Areas (ISAs). At each site, measurements of air temperature, relative humidity, wind speed, and wind ... direction were made at 2 m (North Park) or 4 m (Frasier and Buffalo Pass) above ground level. Snow depth, soil moisture, and soil temperatures were also measured. Hourly meteorological observations were recorded between 20 September 2002 and 1 October 2003, although data were not necessarily continuous throughout this time period for all towers. The NASA CLPX is a multi-sensor, multi-scale experiment that focuses on extending a local-scale understanding of water fluxes, storage, and transformations to regional and global scales. Within a framework of nested study areas in the central Rocky Mountains of the western United States, ranging from 1-ha to 160,000 km^2, intensive ground, airborne, and spaceborne observations are collected. Data collection focuses on two seasons: mid-winter, when conditions are generally frozen and dry; and early spring, a transitional period when both frozen and thawed, dry and wet conditions are widespread.