The work of CB and PD was supported by the state of California through the Public Interest Energy Research Program. The work of DBL was performed under the auspices of the U.S. Department of Energy by University of California and Lawrence Livermore National Laboratory under Contract W-7405-Eng-48. We thank the anonymous reviewers for their substantive comments. We warmly thank Alan Hamlet (University of Washington), Phil Jones (Climatic Research Unit), and Timothy Kittel (University of Colorado) for their advices and for providing the list of stations in California used in the CRUs and the UW gridded datasets.
Bereket, L., , D. Fabris, , J. E. Gonzalez, , S. Chiappari, , S. Zarantonello, , N. L. Miller, , and R. Bornstein, 2005: Urban heat islands in California’s Central Valley. Bull. Amer. Meteor. Soc., 86 , 1542–1543.
Christy, J. R., , W. B. Norris, , K. Redmond, , and K. P. Gallo, 2006: Methodology and results of calculating central California surface temperature trends: Evidence of human-induced climate change? J. Climate, 19 , 548–563.
Duffy, P. B., and Coauthors, 2006: Simulations of present and future climates in the western United States with four nested regional climate models. J. Climate, 19 , 873–895.
Hamlet, A. F., , and D. P. Lettenmaier, 2005: Production of temporally consistent gridded precipitation and temperature fields for the continental United States. J. Hydrometeor., 6 , 330–336.
Karl, T. R., , C. N. Williams Jr., , F. T. Quinlan, , and T. A. Boden, 1990: United States Historical Climatology Network (HCN) serial temperature and precipitation data. Environmental Science Division, Publication No. 3404, Carbon Dioxide Information and Analysis Center, Oak Ridge National Laboratory, Oak Ridge, TN, 389 pp.
Kittel, T. G. F., and Coauthors, 2001: VEMAP 2: U.S. monthly climate, 1895–1993, version 2. Oak Ridge National Laboratory, Oak Ridge, TN. [Available online at http://www.daac.ornl.gov.].
Mitchell, T. D., , and P. D. Jones, 2005: An improved method of constructing a database of monthly climate observations and associated high-resolution grids. Int. J. Climatol., 25 , 693–712.
Mitchell, T. D., , T. R. Carter, , P. D. Jones, , M. Hulme, , and M. New, 2004: A comprehensive set of high-resolution grids of monthly climate for Europe and the globe: The observed record (1901–2000) and 16 scenarios (2001–2100). Tyndall Working Paper 55, Tyndall Centre, University of East Anglia, Norwich, United Kingdom. [Available online at http://www.tyndall.ac.uk/.].
Mote, P. W., , A. F. Hamlet, , M. P. Clark, , and D. P. Lettenmaier, 2005: Declining mountain snowpack in western North America. Bull. Amer. Meteor. Soc., 86 , 39–49.
Santer, B. D., , T. M. L. Wigley, , J. S. Boyle, , D. J. Gaffen, , J. J. Hnilo, , D. Nychka, , D. E. Parker, , and K. E. Taylor, 2000: Statistical significance of trends and trend differences in layer-average atmospheric temperature time series. J. Geophys. Res., 105 , 7337–7356.