Gridded Climate Datasets: NOAA's nClimGrid - Daily

nClimGrid-Daily is a gridded dataset from NOAA's National Centers for Environmental Information (NCEI) that includes area averages of daily maximum, minimum, and average temperatures and daily precipitation amounts for the contiguous United States from January 1, 1951 to the present. The dataset is designed for climate monitoring and other applications that rely on placing event-specific meteorological patterns into a long-term historical context. Data are derived from morning and midnight observations from the Global Historical Climatology Network-Daily (GHCNd) dataset, and contain processing techniques that address the spatial and temporal variations that affect the quality and homogeneity of the fields. 

Area averages are available for common regional groupings, including census tracts, counties, climate divisions, states, major hydrologic units, and Weather Forecast Office regions. Data are also available for report-specific regions from NCEI's climate monitoring reports and the Fifth National Climate Assessment (NCA5). 

The nClimGrid-Daily auxiliary product provides daily gridded fields of counts of the number of Tmax, Tmin, and Prcp observations within 48.3 km (30 miles) of each grid point. These counts were designed to help the U.S. Army Corps of Engineers determine uncertainty in the grid point estimates.