The ORNL DAAC has released two data sets with daily climate values from Phase 2 of the Vegetation/Ecosystem Modeling and Analysis Project (VEMAP).
"VEMAP 2: U.S. Daily Climate, 1895-1993" contains daily measurements of minimum and maximum temperature, precipitation, vapor pressure, solar radiation, irradiance, and relative humidity for the contiguous United States from January 1895 through December 1993.
"VEMAP 2: U.S. Daily Climate Change Scenarios" provides daily climate change scenarios for the period January 1895 to December 2100. The scenarios are based on experiments with coupled atmosphere-ocean general circulation models, and they reflect time-dependent changes in surface climate.
VEMAP is an international project studying the response of biogeochemical models and vegetation-type distribution models to variability in climate and to other spatial and temporal factors.
For more information about VEMAP and associated data, visit the VEMAP project page maintained by the ORNL DAAC.