U.S. Historical Climatology Network (USHCN) Daily Temperature, Precipitation, and Snow Data

The U.S. Historical Climatology Network (USHCN) project arose from the need for an accurate, unbiased, and modern historical climate record suitable for detecting and monitoring secular changes in regional climate in the contiguous United States. The initial work of Quinlan et al. (1987) involved the compilation of a database containing monthly temperature and precipitation data from a network of 1219 U.S. stations. The quality of the HCN data was later enhanced with the use of outlier and areal edits, and the data were corrected for time of observation differences, instrument changes, instrument moves, station relocations, and urbanization effects (Karl et al. 1986; Karl and Williams 1987). The HCN has been updated several times since its inception, most recently by Williams et al. (2004). Some of the stations in the HCN are first-order weather stations, but the majority were selected from approximately 5000 U.S. cooperative weather stations.

The data presented in this package are daily observations of maximum and minimum temperature, precipitation amount (liquid equivalent), snowfall amount, and snow depth from 1062 of the 1221 stations comprising the HCN. Data from 1005 of these daily records extend through 2000, while 920 of these extend through 2005. Most station records are essentially complete for at least 50 years; the latest beginning year of record is 1948. Records from 158 stations begin prior to 1900, with that of Charleston, South Carolina beginning the earliest (1871).

References:

Karl, T. R., G. Kukla, and J. Gavin. 1986. Relationship between decreased temperature range and precipitation trends in the United States and Canada, 1941 80. J. Clim. Appl. Meteor. 25:1878-86.

Karl, T. R., and C. N. Williams, Jr. 1987. An approach to adjusting climatological time series for discontinuous inhomogeneities. J. Clim. Appl. Meteor. 26:1744-63.

Quinlan, F. T., T. R. Karl, and C. N. Williams, Jr. 1987. United States Historical Climatology Network (HCN) serial temperature and precipitation data. NDP-019. Carbon Dioxide Information Analysis Center. Oak Ridge National Laboratory, Oak Ridge, Tennessee.

Williams, C. N., R. S. Vose, D. R. Easterling, and M. J. Menne, 2004. United States Historical Climatology Network Daily Temperature, Precipitation, and Snow Data. ORNL/CDIAC-118, NDP-070. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee.