Since the turn of the century, the National Climatic Data Center (NCDC) has pursued two tracks to preserve the temperature record of the United States: 1) closely monitoring the health of existing observation networks and climate time series, including pursuing a strong program of data quality control and homogenization; 2) building a new U.S. climate observing network adhering to the Global Climate Observing System Climate Monitoring Principles. The US Climate Reference Network (USCRN) is the outcome of the second track. The conterminous U.S. network of 114 stations was completed in 2008, and expansion of the network in Alaska commenced in 2009. Triplicate measurements of temperature with well shielded and ventilated platinum resistance thermometers calibrated using National Institute of Standards and Technology traceable standards yield extremely accurate temperature observations in pristine environments.

Sufficient time series length has accrued since network commissioning in 2004 to be useful in confirming that the temperature record derived operationally from the long existing stations is being corrected accurately and matches well with the USCRN record (Menne et al. 2010, J. Geophy. Res., 115, D11108, doi:10.1029/2009JD013094). This presentation will extend the annual comparison into 2011, and for the first time examine the monthly US temperature record from USCRN in detail, using both departure from estimated normals and first difference approaches.