Skip Links

Scientific Investigations Report 2005–5275

About USGS /  Science Topics /  Maps, Products & Publications /  Education / Publication: FAQ

Computer Program for the Kendall Family of Trend Tests

By Dennis R. Helsel, David K. Mueller, and James R. Slack

Thumbnail of cover and link to PDF (160 KB)Download Publication
SIR 5275
PDF (160 KB)
Right-Click to 'Save As' or 'Download'

The Seasonal Kendall (SK) test for trend was developed by the U.S. Geological Survey and has become the most frequently used test for trend in the environmental sciences. Recently the test was modified to form the Regional Kendall (RK) test for trend. In this form, trends at numerous locations within a region are tested to determine whether the direction of trend is consistent across the entire region. Computer code developed at the USGS in the 1980s to perform the SK test is no longer widely available. Other versions written by other scientists may or may not be easily available, and may require commercial software in order to be run. These other versions do not explicitly compute the RK test. Therefore, the original code for computing the SK test has been repackaged into a program that runs under the Windows operating system. This program may be used to verify that other implementations of the test give the same results as the original. The program also provides a means for computing the RK test and the simpler Mann-Kendall test for trend.

Version 1.0

Posted June 2006

  • Report PDF (173 KB)
    (This version of the report is accessible as defined in Section 508 of the Rehabilitation Act of 1973, Amendments of 1998.)
Associated Kendall files
for download.

Part or all of this report is presented in Portable Document Format (PDF); the latest version of Adobe Acrobat Reader or similar software is required to view it. Download the latest version of Acrobat Reader, free of charge or go to for free tools that allow visually impaired users to read PDF files. logo