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METAR Decoder Software Package Library

The National Weather Service has provided its METAR Decoder Software Package to the public. The MDSP Library is a repackaging and modification of the original MDSP to compile and run on BSD and Linux (and pretty much any other OS).

Clay Hopperdietzel has taken over this project, and has given it a new home on SourceForge. The text of this page can only really be considered relevant to version 0.11, as released way back in 2001.


METAR is a French acronym for Aviation Routine Weather Report. It is the standard format for reporting meteorological conditions. As a free service, the National Weather Service continually updates a server with METARs from all over the world.

About This Library

The MDSP Library provides a programmer with two functions, the major one being DcdMETAR, which decodes a METAR into structures provided by the library. Also prtDMETR, which prints out a decoded METAR structure.

Known Issues


April 28, 2011
Official project page moved to SourceForge.
December 5, 2004
The NWS is now offering weather data feeds in XML. If you are building a new application that will make use of NWS feeds that is probably your best option.
December 10, 2003
This software is now licensed under the LGPL. I also updated the contact info in the README, and added dmetar and libmetar.a to make clean. The code has remained unchanged, so I did not bump the version number.
October 20, 2001
Version 0.11 released. Adds two new functions, dcdNetMETAR() (for METARs from the NWS servers), and sprint_metar(). Also got rid of the bool typedef that was causing problems with C++ programs. Also added a "make install".


Visit the SourceForge project page.