Station Quality Control Status

A major element of the CDMP 19th Century Forts and Voluntary Observers Database Build Project is quality controlling the digitized U.S. daily weather observations.  A number of computerized tests are performed on the CDMP Forts data to improve and ensure the quality of the data.  If outliers are found by these tests, the data are manually checked to assess the correctness of the data, and the data are corrected if found to be clearly in error.

Only stations that have had all quality control tests completed are made available.  If and when additional funding for this program is acquired, additional stations will be quality controlled. Contact Leslie Stoecker or Beth Hall if there are critical stations you wish to have quality controlled.

To see a list of keyed stations sorted by state, availability, or the completeness of quality control tests, select one of the "Go" buttons below. You can also go to an interactive map of keyed stations locations, or static maps for Quality Control complete and QC not complete.

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Description of Tests

The first group of tests concentrates on gross errors in the entirety of the keyed data and inconsistencies between keyed data and metadata.  The primary functions of these three tests are:

The second set of tests focuses on the accuracy of temperature, precipitation, and snowfall elements.  For all three variables, the monthly sum and mean are calculated and compared with those recorded by the observer.  Large differences are flagged for review.  Subjectively determined threshold cut-offs for extreme values also are tested.

For further details on quality control of the 19th century weather data, see this report (pdf).