National Center for Atmospheric Research (NCAR) - CISL Research Data Archive
Data for Atmospheric and Geosciences Research
"This list contains all RDA [Research Data Archive] datasets where some or all of the data are available free of charge. Go to a dataset by clicking on its ID. There you will find more information on how to gain access to the data."
Do not appear to have licensing information. They offer the following as guidelines on acknowledgement:
"If you use our data in published research, we request that you acknowledge NCAR as follows:
The data were provided by the Data Support Section of the
Computational and Information Systems Laboratory at the
National Center for Atmospheric Research. NCAR is
supported by grants from the National Science Foundation.
We also request that you acknowledge the original source(s) of the data, which can be found on the dataset home page."