The weather project employs the ISC license, a permissive free software license written by the Internet Systems Consortium and functionally equivalent to the 2-clause BSD license. Initially used for the ISC's own software releases, it has since become the preferred license of many other projects.
The correlation data provided is augmented by manual research but built primarily by aggregating sources within the USA Public Domain (U.S. Census Bureau Gazetteer and publications of the National Oceanic and Atmospheric Administration's National Climatic Data Center and National Weather Service including its National Centers for Environmental Prediction and Office of Science and Technology/Systems Engineering Center Geographic Information Systems Map Group). Copies of the original external data sources have been provided with this software for reference, but are not covered by the copyright or permission notices which follow.
Copyright (c) 2006-2012 Jeremy Stanley <email@example.com>
Permission to use, copy, modify, and distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.
The software is provided "as is" and the author disclaims all warranties with regard to this software including all implied warranties of merchantability and fitness. In no event shall the author be liable for any special, direct, indirect, or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use or performance of this software.