Turbulence is a significant safety issue for aviation at upper levels in the atmosphere. To aid in turbulence forecasting, the National Center for Atmospheric Research (NCAR), National Oceanic and Atmospheric Association (NOAA), the Federal Aviation Administration (FAA) and some commercial airlines have developed on-board software that records atmospheric turbulence levels every minute during flight. This source of turbulence observations -- termed in-situ data -- is a measurement of the eddy dissipation rate (edr) around an aircraft. In-situ data from 2003-2007 at upper levels were analyzed by geographic location, altitude, season and time of day to develop a detailed climatology of turbulence over the CONUS. The data were normalized to account for regional differences in air traffic density. The results can be used to tailor forecasting algorithm parameters to spatial and temporal variations in upper-level turbulence in an effort to improve operational forecasting accuracy.