The following sites contain downloadable data sets for analysis by subject area. Some of the sites are available for data set deposit, check with your librarian if you are looking to find a repository to deposit your research data.
Climate Data Online (CDO) provides free access to NCDC's archive of global historical weather and climate data in addition to station history information. These data include quality controlled daily, monthly, seasonal, and yearly measurements of temperature, precipitation, wind, and degree days as well as radar data and 30-year Climate Normals.
The Data Observation Network for Earth (DataONE) is a community driven project providing access to data across multiple member repositories, supporting enhanced search and discovery of Earth and environmental data.
The Dryad Digital Repository is a curated resource that makes the data underlying scientific publications discoverable, freely reusable, and citable. Dryad provides a general-purpose home for a wide diversity of datatypes.
GenBank ® is the NIH genetic sequence database, an annotated collection of all publicly available DNA sequences. A GenBank release occurs every two months and is available from the ftp site.
A freely accessible collection of data relating to biologically-active small molecules, including compound structure, synonyms, descriptions, and bio-activity. Provided by the National Center for Biotechnology Information (NCBI).
Phenology data are already supporting science and helping natural resource managers and public officials make decisions about how to prepare for and cope with the rapid changes occurring across the nation.