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Meteorological Database, Argonne National Laboratory, Illinois, January 1, 1948 - September 30, 2016

August 23, 2017

This data release is the update of the U.S. Geological Survey - ScienceBase data release by Bera and Over (2016), with the processed data through September 30, 2016. The primary data for each year is downloaded from the Argonne National Laboratory (ANL) ( and is processed following the guidelines documented in Over and others (2010) and Bera (2014). Daily potential evapotranspiration (PET) in thousandths of an inch is computed from average daily air temperature in degrees Fahrenheit (F), average daily dewpoint temperature in degrees Fahrenheit (F), daily total wind movement in miles (mi), and daily total solar radiation in Langleys per day (Lg/d) and disaggregated to hourly PET in thousandths of an inch using the Fortran program LXPET (Murphy, 2005). Missing and apparently erroneous data values were replaced with adjusted values from nearby stations used as backup. As stated in Over and others (2010), temporal variations in the statistical properties of the data resulting from changes in measurement and data storage methodologies were adjusted to match the statistical properties resulting from the data collection procedures that have been in place since January 1, 1989. The adjustments were computed based on the regressions between the primary data series from ANL and the backup series using data obtained during common periods; the statistical properties of the regressions were used to assign estimated standard errors to values that were adjusted or filled from other series. Each hourly value is assigned a corresponding data-source flag that indicates the source of the value and its transformations. As described in Over and others (2010), each flag is of the form "xyz" that allows the user to determine its source and the methods used to process the data. During the period 01/09/2016 hour 21 to 01/10/2016 hour 24, both ANL and the primary backup station at St. Charles, Illinois had missing wind speed data. The O'Hare International Airport (ORD) is used as an alternate backup station and the new regression equation and the corresponding new data-source flag for wind speed data are established using daily total wind speed data from ORD for the period 10/01/2007 through 09/30/2016 following the guidelines described in Over and others (2010). The detail is given in the child page containing wind speed data and the associated data-source flag.